Reland 'Apply uid of original caller when starting LE scan by PendingIntent'

- When starting LE scan by PendingItent, uid of btservice was applied in
  ScanClient. ScanManager misunderstood the ScanClient is owned by
  foreground service.
- This fix is to apply the uid of orignal caller so that
  ScanManager decides scan policy correctly.
- Verified in multi user settings

Bug: 299231195
Bug: 300866864
Test: atest BluetoothInstrumentationTests and device test
Change-Id: I97fa1af47401c9674dd12fd835ec6f8e7abde35c