Remove fallback workaround for APEX variants which is now unnecessary.

Test: m nothing
Bug: 191269918
Change-Id: I13091d5ffdd46947899db273b9cb2399dda23907
diff --git a/apex/apex.go b/apex/apex.go
index add506f..b47f36b 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1100,13 +1100,6 @@
 			mctx.ModuleErrorf("base property is not set")
 			return
 		}
-		// Workaround the issue reported in b/191269918 by using the unprefixed module name of this
-		// module as the default variation to use if dependencies of this module do not have the correct
-		// apex variant name. This name matches the name used to create the variations of modules for
-		// which apexModuleTypeRequiresVariant return true.
-		// TODO(b/191269918): Remove this workaround.
-		unprefixedModuleName := android.RemoveOptionalPrebuiltPrefix(mctx.ModuleName())
-		mctx.SetDefaultDependencyVariation(&unprefixedModuleName)
 		mctx.CreateVariations(apexBundleName)
 		if strings.HasPrefix(apexBundleName, "com.android.art") {
 			// TODO(b/183882457): See note for CreateAliasVariation above.