Update git submodules

* Update platform/cts from branch 'master'
  to 4c7b9688c58f471a8d0b04afe64e66d4e1933a57
  - Merge "Add coverage for bluetooth API"
  - Add coverage for bluetooth API
    
    Bug: 217352944
    Test: atest 'CtsBluetoothTestCases:android.bluetooth.cts.BluetoothAdapterTest'
    Test: atest 'CtsBluetoothTestCases:android.bluetooth.cts.BluetoothA2dpSinkTest'
    Test: atest 'CtsBluetoothTestCases:android.bluetooth.cts.BluetoothA2dpTest'
    Test: atest 'CtsBluetoothTestCases:android.bluetooth.cts.BluetoothSapTest'
    Tag: #refactor
    Merged-In: If05fd3866d2be4e52c270f4863f3a970cdb806aa
    Change-Id: If05fd3866d2be4e52c270f4863f3a970cdb806aa