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
1 file changed