Merge "Fix concurrent external vibrations on ExternalVibratorService" into sc-dev am: 1dd6f20e am: 6ccbe780 am: 64db2da3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15243095

Change-Id: I71292f9ab2a0cc2c7123af60fa44b4bdbb1fc4d3