Fix includes of SkRRect and other Skia headers

I would like to (re-)land https://skia-review.googlesource.com/c/skia/+/512158
which tidies up includes around SkRRect. I searched for all
places in libs/hwui that used SkRRect and made sure they either
forward declared it or included it, as appropriate.

While going through these files, I fixed a few other includes that
stood out to me, e.g. SkPaint, SkCanvas, etc to make sure the files
that use the symbols are the ones including them (and lessening
transitive dependencies).

Change-Id: I44792a6b9f06a54d052cefa4cbc9342f46ab2a4f
diff --git a/libs/hwui/pipeline/skia/DumpOpsCanvas.h b/libs/hwui/pipeline/skia/DumpOpsCanvas.h
index 3f89c07..6a052db 100644
--- a/libs/hwui/pipeline/skia/DumpOpsCanvas.h
+++ b/libs/hwui/pipeline/skia/DumpOpsCanvas.h
@@ -19,6 +19,8 @@
 #include "RenderNode.h"
 #include "SkiaDisplayList.h"
 
+class SkRRect;
+
 namespace android {
 namespace uirenderer {
 namespace skiapipeline {