[automerger skipped] Add placeholder when media control title is blank am: df4686dc0a -s ours

am skip reason: Merged-In Ie406c180af48653595e8e222a15b4dda27de2e0e with SHA-1 a0fda1f36d is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23497629

Change-Id: I2839d860b9c7e1b4b5d1584a4a824d18977a3203
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>