Reset descriptions for SeekBarPreference

The view maybe reuse and the content/state descriptions need to be clean
up, otherwise it'll be the old view's description.

Flag: EXEMPT bugfix
Bug: 382608695
Test: manual test with TalkBack on
Change-Id: I7bc522770e7cdc8c1ef7b05b410e69af7e2d4b4b

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

@@ -142,9 +142,13 @@ public class SeekBarPreference extends RestrictedPreference
             mSeekBar.setContentDescription(mSeekBarContentDescription);
         } else if (!TextUtils.isEmpty(title)) {
             mSeekBar.setContentDescription(title);
+        } else {
+            mSeekBar.setContentDescription(null);
         }
         if (!TextUtils.isEmpty(mSeekBarStateDescription)) {
             mSeekBar.setStateDescription(mSeekBarStateDescription);
+        } else {
+            mSeekBar.setStateDescription(null);
         }
         if (mSeekBar instanceof DefaultIndicatorSeekBar) {
             ((DefaultIndicatorSeekBar) mSeekBar).setDefaultProgress(mDefaultProgress);