hwc/copybit: Add check for Max layers support.

Add check in copybit for Max. layers supported by HWC. Increase
max. RGB surfaces to MAX_NUM_LAYERS to support known use cases.

CRs-Fixed: 481226
Change-Id: Ie30ab0ef3047a304133cb547902ae11fecc5db22
diff --git a/libhwcomposer/hwc_copybit.cpp b/libhwcomposer/hwc_copybit.cpp
index 3f40753..f1bf756 100644
--- a/libhwcomposer/hwc_copybit.cpp
+++ b/libhwcomposer/hwc_copybit.cpp
@@ -158,6 +158,11 @@
         return false;
     }
 
+    if (ctx->listStats[dpy].numAppLayers > MAX_NUM_LAYERS) {
+        // Reached max layers supported by HWC.
+        return false;
+    }
+
     bool useCopybitForYUV = canUseCopybitForYUV(ctx);
     bool useCopybitForRGB = canUseCopybitForRGB(ctx, list, dpy);
     LayerProp *layerProp = ctx->layerProp[dpy];