[RESTRICT AUTOMERGE] Fix Keyboard shown after force stopped app package

CL[1] add a check in IMMS#hideCurrentInputLocked to
ignore hide request when the current client or the current
input session is null for preventing switching IME may have
unexpected keyboard hidden when focusing the same window to
start input case.

A regression happens when forcing stop the app with focusing a editor
and show soft-keyboard, because the hide request ignored as the above
mentioned, so keyboard will be shown after the next input connection
started since the mShowRequested didn't set to false by hidden request.

As CL[2] uses sameWindowFocused to check all possible hide current
keyboard call places in startInputOrWindowGainedFocusInternalLocked to
hide soft-keyboard only when the window focus changes, so we should
revert the check in IMMS#hideCurrentInputLocked to fix this keyboard
visiblity issue.

[1]: I37ae6e30d1de581ba15131c2a90396b3a522a4d6
[2]: I20e8076acc5fec3c055af0740e2e2a64b1fb6f0d

Note that the QPR version of [1] already includes the follow-up
changes in [2].

Fixes: 171009669
Test: atest KeyboardVisibilityControlTest
Change-Id: I92accb513b728820a3043b365aa5fa4f3a1a34a5
diff --git a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
index bcfbcd1..47008a7 100644
--- a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
@@ -3275,9 +3275,6 @@
 
     boolean hideCurrentInputLocked(IBinder windowToken, int flags, ResultReceiver resultReceiver,
             @SoftInputShowHideReason int reason) {
-        if (mCurClient == null || mCurClient.curSession == null) {
-            return false;
-        }
         if ((flags&InputMethodManager.HIDE_IMPLICIT_ONLY) != 0
                 && (mShowExplicitlyRequested || mShowForced)) {
             if (DEBUG) Slog.v(TAG, "Not hiding: explicit show not cancelled by non-explicit hide");