Rename modulesAddedWall to modulesWarningsAllowed

MODULES_ADDED_WALL is deceiving and it actually meant which modules are
allowed to have warnings (do not automatically append -Werror flag).

Test: presubmit
Bug: 233183337
Change-Id: Ibd21e269eba04d01f13026d70a9e34ccb1cf26d7
diff --git a/cc/makevars.go b/cc/makevars.go
index 6752f8c..8154436 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -25,7 +25,7 @@
 )
 
 var (
-	modulesAddedWallKey          = android.NewOnceKey("ModulesAddedWall")
+	modulesWarningsAllowedKey    = android.NewOnceKey("ModulesWarningsAllowed")
 	modulesUsingWnoErrorKey      = android.NewOnceKey("ModulesUsingWnoError")
 	modulesMissingProfileFileKey = android.NewOnceKey("ModulesMissingProfileFile")
 )
@@ -119,7 +119,7 @@
 	ctx.Strict("LSDUMP_PATHS", strings.Join(lsdumpPaths, " "))
 
 	ctx.Strict("ANDROID_WARNING_ALLOWED_PROJECTS", makeStringOfWarningAllowedProjects())
-	ctx.Strict("SOONG_MODULES_ADDED_WALL", makeStringOfKeys(ctx, modulesAddedWallKey))
+	ctx.Strict("SOONG_MODULES_WARNINGS_ALLOWED", makeStringOfKeys(ctx, modulesWarningsAllowedKey))
 	ctx.Strict("SOONG_MODULES_USING_WNO_ERROR", makeStringOfKeys(ctx, modulesUsingWnoErrorKey))
 	ctx.Strict("SOONG_MODULES_MISSING_PGO_PROFILE_FILE", makeStringOfKeys(ctx, modulesMissingProfileFileKey))