Fully qualify @attr reference to android.R field

Currently, Metalava has some special handling of '@attr ref R.<field>`
references to make sure that they are fully qualified, i.e.
`@attr ref android.R.<field>`. That special handling complicates
Metalava and is blocking some flagged API work so will be removed.
Before that can be done, the existing incorrect documentation needs to
be cleaned up.

This change cleans up those cases in this repo.

Bug: 371997321
Test: Run `m offline-sdk-docs` before and after to make sure that
      there are no differences.
Flag: DOCS_ONLY
Change-Id: Ic97f01b90193d058d65e6d3c6d0a04ce5e55d7c7

src/com/android/settings/widget/TintDrawable.java

@@ -39,7 +39,7 @@ import java.io.IOException;
  * underlying drawable. This class should only be used in XML.
  *
  * @attr ref android.R.styleable#DrawableWrapper_drawable
- * @attr ref R.styleable#TintDrawable_tint
+ * @attr ref android.R.styleable#TintDrawable_tint
  */
 public class TintDrawable extends DrawableWrapper {
     private ColorStateList mTint;