Do not capture screenshot when copy bitmap fails

Author: romtsn

sentry-android-core/src/main/java/io/sentry/android/core/ScreenshotEventProcessor.java

@@ -210,7 +210,7 @@ private boolean isMaskingEnabled() {
       if (!screenshot.isMutable()) {
         mutableBitmap = screenshot.copy(Bitmap.Config.ARGB_8888, true);
         if (mutableBitmap == null) {
-          return screenshot;
+          return null;
         }
         createdCopy = true;
       }