Merge "Remove M4 export to Make" am: a6ba0d2a4c am: 50e7c7f0c6

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1393489

Change-Id: Ib23151fb899979a7bd168346dd3603e69b8e6f33

cc/makevars.go

@@ -148,8 +148,6 @@ func makeVarsProvider(ctx android.MakeVarsContext) {
 	ctx.Strict("AIDL_CPP", "${aidlCmd}")
 	ctx.Strict("ALLOWED_MANUAL_INTERFACE_PATHS", strings.Join(allowedManualInterfacePaths, " "))
 
-	ctx.Strict("M4", "${m4Cmd}")
-
 	ctx.Strict("RS_GLOBAL_INCLUDES", "${config.RsGlobalIncludes}")
 
 	ctx.Strict("SOONG_STRIP_PATH", "${stripPath}")