Revert^2 "Reuse mHandler AdbKeyStore to fetch paired devices"

Reason for revert: reverting changes after ag/35289549

Test: AdbDebuggingManagerTest
Test lunch sdk_gphone64_x86_64-trunk_staging-userdebug && m && ./prebuilts/android-emulator/linux-x86_64/emulator -wipe-data -show-kernel
Bug: 420613813
Flag: EXEMPT bugfix

Change-Id: Ib3910d34cd9e27e7db13b4776135261dc7fe41dc