Adjustments after moving MediaStore inside APEX.

The "core_platform" SDK technically includes non-stable APIs, so we
need to shift to "core_current" instead.

While we're here, tidy up some older @removed APIs that never shipped
and replace HexEncoding with a local implementation.

Since MediaProvider itself is free to use @hide APIs from its own
framework code in MediaStore.java, we can include all sources
from "framework-mediaprovider-sources" directly.

Also since the "framework-annotations" filegroup in Android.bp is
a very limited subset of leaf source code, it can't directly
reference Intent, so adjust the javadoc so we can drop the "import."

Bug: 144247087
Test: atest --test-mapping packages/providers/MediaProvider
Change-Id: I198d84a755b5e270a19b41328f6a6e152112c40a
diff --git a/java/android/annotation/RequiresPermission.java b/java/android/annotation/RequiresPermission.java
index 59d419f..e5c0654 100644
--- a/java/android/annotation/RequiresPermission.java
+++ b/java/android/annotation/RequiresPermission.java
@@ -15,8 +15,6 @@
  */
 package android.annotation;
 
-import android.content.Intent;
-
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
@@ -57,7 +55,7 @@
  * <p>
  * When specified on a parameter, the annotation indicates that the method requires
  * a permission which depends on the value of the parameter. For example, consider
- * {@link android.app.Activity#startActivity(Intent)}:
+ * {@link android.app.Activity#startActivity(android.content.Intent)}:
  * <pre>{@code
  *   public void startActivity(@RequiresPermission Intent intent) { ... }
  * }</pre>