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.

Bug: 299231195
Test: atest BluetoothInstrumentationTests and device test
Change-Id: I32e0cca8735fa260cd4d57d47ccf571f37b99fa4