Merge "Revert "Removed BluetoothDevice#prepareToEnterProcess"" am: 168b5655a4 am: a3b55d5079 am: 170597987c am: fddbf6e930 am: 92bf843da4

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

Change-Id: Ib926a6c45bead4e50de93a371b97bfadad2a9fb0