Merge "Revert "Removed BluetoothDevice#prepareToEnterProcess"" am: 168b5655a4 am: a3b55d5079 am: 170597987c

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1869964

Change-Id: I20da6815471e8e19813d16f9785d3238d29e46c1