[Android.bp] Add cflags, include_dirs, shared_libs ans srcs to ARC++ Product

Test: Compile
Bug: None
Change-Id: I422f2194208ea14e976970de748d6d9238fe9f14

android/variable.go

@@ -103,8 +103,12 @@ type variableProperties struct {
 		}
 
 		Arc struct {
+			Cflags       []string
 			Exclude_srcs []string
+			Include_dirs []string
+			Shared_libs  []string
 			Static_libs  []string
+			Srcs         []string
 		}
 	} `android:"arch_variant"`
 }