Merge "Shows blurred thumbnail before fading to live preview" into tm-qpr-dev am: 31d25c7bb4 am: 2996ad8b13

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/22338419

Change-Id: Ibf863ef60649e6b54a0e176e1685dc4ef66a7314
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>