Update vts test to use the updated test template.

* For registerTestService/getServiceName, no need to pass
  any hard coded string of HAL service FQName.
* Affect test: VtsHalCameraProviderV2_4TargetTest,
               VtsHalGraphicsComposerV2_1TargetTest,
               VtsHalNeuralnetworksV1_0TargetTest

Bug: 62946472
Bug: 64203181

Test: make vts
      vts-tradefed run vts -m VtsHalCameraProviderV2_4Target

Change-Id: Id0bddbc2949337147557f45cc60dbfaa114ce25e