drm_hwcomposer: Move HwcLayer out of DrmHwcTwo class

... to reduce complexity of DrmHwcTwo.* files.

Bump-up tidy level of new files to NORMAL (fix function naming,
add NOLINT, etc.)

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/backend/BackendRCarDu.h b/backend/BackendRCarDu.h
index 8a1011a..862bef2 100644
--- a/backend/BackendRCarDu.h
+++ b/backend/BackendRCarDu.h
@@ -23,8 +23,7 @@
 
 class BackendRCarDu : public Backend {
  public:
-  bool IsClientLayer(DrmHwcTwo::HwcDisplay *display,
-                     DrmHwcTwo::HwcLayer *layer) override;
+  bool IsClientLayer(DrmHwcTwo::HwcDisplay *display, HwcLayer *layer) override;
 };
 }  // namespace android