Allow modules to be enabled/disabled depending on whether APEXes are flattened.

Allow the `enabled` Soong/Blueprint property (e.g. in `genrule` and
`cc_prebuilt_binary` module definitions) to have a different value
when APEX flattening is enabled.

Test: m checkbuild
Bug: 139277987
Change-Id: Ic586bdfac7690077445da12543154381d92cf98e
Merged-In: Ic586bdfac7690077445da12543154381d92cf98e

android/variable.go

@@ -115,6 +115,10 @@ type variableProperties struct {
 			Static_libs  []string
 			Srcs         []string
 		}
+
+		Flatten_apex struct {
+			Enabled *bool
+		}
 	} `android:"arch_variant"`
 }