Make some common properties overridden when used in defaults modules

Switch commonProperties to *string and *bool so that defining them
in a module correctly overrides instead of appends to values set
in defaults modules.

Bug: 68337468
Test: m checkbuild
Change-Id: I70e45caa92f65dc6a3bc81ae33a5a8f34ad11890
diff --git a/android/androidmk.go b/android/androidmk.go
index 759d328..2cae1c3 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -231,10 +231,10 @@
 		if len(amod.commonProperties.Init_rc) > 0 {
 			fmt.Fprintln(&data.preamble, "LOCAL_INIT_RC := ", strings.Join(amod.commonProperties.Init_rc, " "))
 		}
-		if amod.commonProperties.Proprietary {
+		if Bool(amod.commonProperties.Proprietary) {
 			fmt.Fprintln(&data.preamble, "LOCAL_PROPRIETARY_MODULE := true")
 		}
-		if amod.commonProperties.Vendor {
+		if Bool(amod.commonProperties.Vendor) {
 			fmt.Fprintln(&data.preamble, "LOCAL_VENDOR_MODULE := true")
 		}
 		if amod.commonProperties.Owner != nil {