Allow ignoring return values when checking if class is mockable

Test: make -j javac-check RUN_ERROR_PRONE=true
Change-Id: I5094fa145fc5f6d5c5d9426b07d764c07e545819
diff --git a/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/ImageReaderTest.java b/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/ImageReaderTest.java
index f6cd990..2cb5704 100644
--- a/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/ImageReaderTest.java
+++ b/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/ImageReaderTest.java
@@ -41,6 +41,7 @@
     private Image mImage3;
 
     @Override
+    @SuppressWarnings("CheckReturnValue")
     protected void setUp() throws Exception {
         super.setUp();