Add Auto Batch Scan Feature

- converts regular to batch scan with low duty cycle when screen is
  turned off
- reverts back to regular scan in turning on screen afer flushing the
  batched scan results
- adds unit test cases for auto batch scan

Bug: 261228018
Test: atest BluetoothInstrumentationTests and end-to-end device test
Test: atest FrameworkBluetoothTests
Tag: #feature
Change-Id: I654e97cc5775a2a6226f2627aa8e4e84f3e25234