Remove extraneous variation name from OverrideApex

Apexes use an empty variation name for themselves, and only set an
extra variation string for dependencies.  OverrideApex is setting
the variation name for itself, which doesn't match apexes and is
unnecessary.

Test: go test ./apex
Change-Id: I6e726c497ccf10f145cda149bd19849fd22dd20b
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 1382f69..ef863f4 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -11368,7 +11368,7 @@
 		variation := func(moduleName string) string {
 			ret := "android_common_com.android.foo"
 			if moduleName == "com.google.android.foo" {
-				ret = "android_common_com.google.android.foo_com.google.android.foo"
+				ret = "android_common_com.google.android.foo"
 			}
 			return ret
 		}
@@ -11883,7 +11883,7 @@
 		}
 	`)
 
-	java.CheckModuleHasDependency(t, res.TestContext, "myoverrideapex", "android_common_myoverrideapex_myoverrideapex", "foo")
+	java.CheckModuleHasDependency(t, res.TestContext, "myoverrideapex", "android_common_myoverrideapex", "foo")
 }
 
 func TestUpdatableApexMinSdkVersionCurrent(t *testing.T) {