Fix behavior of stencil clipping within clearLayerRegions

bug:16376960

The draw within clearLayerRegions should never be affected by the
current stencil clip, since it's just ensuring that the content of the
layer is cleared, and not doing real content drawing.

Also, add optional verbose GL event logging

Change-Id: I538b1bc631fc091340b76e12db6af0c219851b57
diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index 9311f99..13265a9 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -27,7 +27,7 @@
 namespace android {
 namespace uirenderer {
 
-#define RECT_STRING "%7.2f %7.2f %7.2f %7.2f"
+#define RECT_STRING "%5.2f %5.2f %5.2f %5.2f"
 #define RECT_ARGS(r) \
     (r).left, (r).top, (r).right, (r).bottom
 #define SK_RECT_ARGS(r) \