Camera: Add support for testing partial results

Currently the result handling is very basic. Partial
results and inflight queues are not supported. More
elaborate test cases like burst or streaming will
require such functionality to be present.

Bug: 62550376
Bug: 37533777
Test: adb shell
/data/nativetest/VtsHalCameraProviderV2_4TargetTest/VtsHalCameraProviderV2_4TargetTest

Change-Id: I3769d4ccc0047dc4eda173ea3bca538b026be8d2