Camera: fix NPE in verifyFpsNotSlowDown

Bug: 30980572
Change-Id: Iae20835ca6e722dbe53a085f2f962aaa91f198d6
diff --git a/tests/camera/src/android/hardware/camera2/cts/CaptureRequestTest.java b/tests/camera/src/android/hardware/camera2/cts/CaptureRequestTest.java
index ebda3dd..ae5c2ea 100644
--- a/tests/camera/src/android/hardware/camera2/cts/CaptureRequestTest.java
+++ b/tests/camera/src/android/hardware/camera2/cts/CaptureRequestTest.java
@@ -2622,7 +2622,7 @@
             }
         }
 
-        mSession.stopRepeating();
+        stopPreview();
     }
 
     /**
diff --git a/tests/camera/src/android/hardware/camera2/cts/testcases/Camera2SurfaceViewTestCase.java b/tests/camera/src/android/hardware/camera2/cts/testcases/Camera2SurfaceViewTestCase.java
index 8d141c4..a95f4f3 100644
--- a/tests/camera/src/android/hardware/camera2/cts/testcases/Camera2SurfaceViewTestCase.java
+++ b/tests/camera/src/android/hardware/camera2/cts/testcases/Camera2SurfaceViewTestCase.java
@@ -222,9 +222,11 @@
      * Does _not_ wait for the device to go idle
      */
     protected void stopPreview() throws Exception {
-        if (VERBOSE) Log.v(TAG, "Stopping preview");
         // Stop repeat, wait for captures to complete, and disconnect from surfaces
-        mSession.close();
+        if (mSession != null) {
+            if (VERBOSE) Log.v(TAG, "Stopping preview");
+            mSession.close();
+        }
     }
 
     /**
@@ -232,11 +234,13 @@
      * resulting in an idle device.
      */
     protected void stopPreviewAndDrain() throws Exception {
-        if (VERBOSE) Log.v(TAG, "Stopping preview and waiting for idle");
         // Stop repeat, wait for captures to complete, and disconnect from surfaces
-        mSession.close();
-        mSessionListener.getStateWaiter().waitForState(BlockingSessionCallback.SESSION_CLOSED,
-                /*timeoutMs*/WAIT_FOR_RESULT_TIMEOUT_MS);
+        if (mSession != null) {
+            if (VERBOSE) Log.v(TAG, "Stopping preview and waiting for idle");
+            mSession.close();
+            mSessionListener.getStateWaiter().waitForState(BlockingSessionCallback.SESSION_CLOSED,
+                    /*timeoutMs*/WAIT_FOR_RESULT_TIMEOUT_MS);
+        }
     }
 
     /**