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/arch.go b/android/arch.go
index eaa35a4..f8317bb 100644
--- a/android/arch.go
+++ b/android/arch.go
@@ -312,12 +312,12 @@
 		var multilib string
 		switch class {
 		case Device:
-			multilib = module.base().commonProperties.Target.Android.Compile_multilib
+			multilib = String(module.base().commonProperties.Target.Android.Compile_multilib)
 		case Host, HostCross:
-			multilib = module.base().commonProperties.Target.Host.Compile_multilib
+			multilib = String(module.base().commonProperties.Target.Host.Compile_multilib)
 		}
 		if multilib == "" {
-			multilib = module.base().commonProperties.Compile_multilib
+			multilib = String(module.base().commonProperties.Compile_multilib)
 		}
 		if multilib == "" {
 			multilib = module.base().commonProperties.Default_multilib