Revert "Revert "[SurfaceFlinger] Add GPU protected content support.""

This reverts commit 78fb96f3f8b40cba6b9e2cb2b0c332a45798b522.
Reason for revert: Revert the revert with Fix.

BUG: 35315015
Test: Test with a hacked patch.
Test: Watch Youtube movie, verifed by force GPU composition.
Change-Id: Ic738b5f873dbff322473d4f999074dc35c8813c7
diff --git a/libs/renderengine/gl/GLImage.cpp b/libs/renderengine/gl/GLImage.cpp
index a9529a7..587cb31 100644
--- a/libs/renderengine/gl/GLImage.cpp
+++ b/libs/renderengine/gl/GLImage.cpp
@@ -65,6 +65,7 @@
             ALOGE("failed to create EGLImage: %#x", eglGetError());
             return false;
         }
+        mProtected = isProtected;
     }
 
     return true;