Add flag support in bluetooth + satellite flag

Flag value can be set with:
adb shell device_config put bluetooth \
  com.android.bluetooth.flags.use_new_satellite_mode true

Bug: 289584302
Test: m service-bluetooth
Test: atest ServiceBluetoothRoboTests
Test: atest com.android.server.bluetooth.satellite.test.ModeListenerTest
Change-Id: Ia834998d19e88ba15e871711dbeb6bcd4a302d03