Fix TB focus on blocked wallpaper preview pager

 - Add BottomSheetBehavior callback to check it's collapsed/expanded state, disable previewpager's a11y param when expended
 - Remove unused code and logic (related with NEW_SCROLL_INTERACTION)
 video: https://drive.google.com/file/d/1G-N_I9QZZRqfDY-2uLvopxTtcT3xTI9d/view?usp=sharing

 Bug: 160284173
 Test: manually

Change-Id: I9db1ce80623420e32bdb3a03e8446b83a0995073
diff --git a/src/com/android/wallpaper/picker/CategoryFragment.java b/src/com/android/wallpaper/picker/CategoryFragment.java
index 9881bec..564d939 100755
--- a/src/com/android/wallpaper/picker/CategoryFragment.java
+++ b/src/com/android/wallpaper/picker/CategoryFragment.java
@@ -17,9 +17,9 @@
 
 import static android.view.View.MeasureSpec.EXACTLY;
 import static android.view.View.MeasureSpec.makeMeasureSpec;
-import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 
 import static com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_COLLAPSED;
+import static com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_EXPANDED;
 
 import android.app.Activity;
 import android.app.WallpaperColors;
@@ -131,9 +131,6 @@
     private static final String PERMISSION_READ_WALLPAPER_INTERNAL =
             "android.permission.READ_WALLPAPER_INTERNAL";
 
-    private static final boolean NEW_SCROLL_INTERACTION =
-            IndividualPickerFragment.NEW_SCROLL_INTERACTION;
-
     private ImageView mHomePreview;
     private SurfaceView mWorkspaceSurface;
     private WorkspaceSurfaceHolderCallback mWorkspaceSurfaceCallback;
@@ -245,30 +242,19 @@
 
         ViewGroup fragmentContainer = view.findViewById(R.id.category_fragment_container);
         mBottomSheetBehavior = BottomSheetBehavior.from(fragmentContainer);
-        if (!NEW_SCROLL_INTERACTION) {
-            fragmentContainer.getLayoutParams().height = MATCH_PARENT;
-            mBottomSheetBehavior.setBottomSheetCallback(
-                    new BottomSheetBehavior.BottomSheetCallback() {
-                        @Override
-                        public void onStateChanged(@NonNull View bottomSheet, int newState) {
-                            if (mIsCollapsingByUserSelecting) {
-                                mIsCollapsingByUserSelecting = newState != STATE_COLLAPSED;
-                                return;
-                            }
+        mBottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
+            @Override
+            public void onStateChanged(@NonNull View bottomSheet, int newState) {
+                // Update preview pager's accessibility param since it will be blocked by the
+                // bottom sheet when expanded.
+                mPreviewPager.setImportantForAccessibility(newState == STATE_EXPANDED
+                        ? View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS
+                        : View.IMPORTANT_FOR_ACCESSIBILITY_YES);
+            }
 
-                            if (mIndividualPickerFragment != null
-                                    && mIndividualPickerFragment.isVisible()) {
-                                mIndividualPickerFragment.resizeLayout(newState == STATE_COLLAPSED
-                                        ? mBottomSheetBehavior.getPeekHeight() : MATCH_PARENT);
-                            }
-                        }
-
-                        @Override
-                        public void onSlide(@NonNull View bottomSheet, float slideOffset) {
-
-                        }
-                    });
-        }
+            @Override
+            public void onSlide(@NonNull View bottomSheet, float slideOffset) {}
+        });
         mRootContainer = view.findViewById(R.id.root_container);
         fragmentContainer.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
             @Override
diff --git a/src/com/android/wallpaper/picker/individual/IndividualPickerFragment.java b/src/com/android/wallpaper/picker/individual/IndividualPickerFragment.java
index f4809ce..53617f5 100755
--- a/src/com/android/wallpaper/picker/individual/IndividualPickerFragment.java
+++ b/src/com/android/wallpaper/picker/individual/IndividualPickerFragment.java
@@ -112,8 +112,6 @@
         SetWallpaperErrorDialogFragment.Listener, SetWallpaperDialogFragment.Listener,
         StartRotationDialogFragment.Listener {
 
-    public static final boolean NEW_SCROLL_INTERACTION = true;
-
     /**
      * Position of a special tile that doesn't belong to an individual wallpaper of the category,
      * such as "my photos" or "daily rotation".
@@ -454,14 +452,6 @@
     }
 
     @Override
-    public void onDestroyView() {
-        if (!NEW_SCROLL_INTERACTION) {
-            updateThumbnail(null);
-        }
-        super.onDestroyView();
-    }
-
-    @Override
     public void onClickTryAgain(@Destination int unused) {
         if (mPendingSetIndividualHolder != null) {
             mPendingSetIndividualHolder.setWallpaper();
@@ -1270,10 +1260,6 @@
                     (isWallpaperApplied && !hasUserSelectedWallpaper) || isWallpaperSelected);
             holder.itemView.findViewById(R.id.check_circle).setVisibility(
                     isWallpaperApplied ? View.VISIBLE : View.GONE);
-            if (!NEW_SCROLL_INTERACTION) {
-                holder.itemView.findViewById(R.id.tile).setOnClickListener(
-                        view -> onWallpaperSelected(wallpaper, position));
-            }
         }
     }