CTS: Fixes for android.hardware.cts.CameraTest#testPreviewCallback

- setPreviewDisplay() was omitted during the individual
  preview resolution tests. The camera documentation states
  that a call to either setPreviewDisplay() or setPreviewTexture()
  is necessary in order to start the preview. Apart from
  that setPreviewDisplay() is mandatory on platforms, which utilize
  an overlay for camera preview.

Change-Id: Ifd2ce8d787a8c1d6790701b9d04f13f4158227d0
diff --git a/tests/tests/hardware/src/android/hardware/cts/CameraTest.java b/tests/tests/hardware/src/android/hardware/cts/CameraTest.java
index 45bc87e..ef8490d 100644
--- a/tests/tests/hardware/src/android/hardware/cts/CameraTest.java
+++ b/tests/tests/hardware/src/android/hardware/cts/CameraTest.java
@@ -405,10 +405,8 @@
             parameters.setPreviewSize(size.width, size.height);
             mCamera.setParameters(parameters);
             assertEquals(size, mCamera.getParameters().getPreviewSize());
-            mCamera.startPreview();
-            waitForPreviewDone();
+            checkPreviewCallback();
             assertTrue(mPreviewCallbackResult);
-            mCamera.stopPreview();
             try {
                 // Wait for a while to throw away the remaining preview frames.
                 Thread.sleep(1000);