Revert "Add override_module."

This reverts commit aa65e17016152d0d73cd10ab3987bc3bd5c2ef91.

Reason for revert: Not compatible with PRODUCT_PACKAGES, and so has very limited use.

Change-Id: Ib141d3984a6f12bb50989e66037494c466b066f1
diff --git a/java/app.go b/java/app.go
index 08b2d91..c08aefd 100644
--- a/java/app.go
+++ b/java/app.go
@@ -392,7 +392,7 @@
 func (a *AndroidApp) getCertString(ctx android.BaseContext) string {
 	certificate, overridden := ctx.DeviceConfig().OverrideCertificateFor(ctx.ModuleName())
 	if overridden {
-		return certificate
+		return ":" + certificate
 	}
 	return String(a.appProperties.Certificate)
 }
diff --git a/java/app_test.go b/java/app_test.go
index 313844f..317c752 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -747,57 +747,3 @@
 		})
 	}
 }
-
-func TestOverrideModule(t *testing.T) {
-	ctx := testJava(t, `
-		android_app {
-			name: "foo",
-			srcs: ["a.java"],
-		}
-
-		override_module {
-			name: "bar",
-			base: "foo",
-			certificate: ":new_certificate",
-			manifest_package_name: "org.dandroid.bp",
-		}
-
-		android_app_certificate {
-			name: "new_certificate",
-	    certificate: "cert/new_cert",
-		}
-		`)
-
-	// The base module still contains all the final outputs after overrides.
-	foo := ctx.ModuleForTests("foo", "android_common")
-
-	// Check the final apk name
-	outputs := foo.AllOutputs()
-	e := buildDir + "/target/product/test_device/system/app/bar/bar.apk"
-	found := false
-	for _, o := range outputs {
-		if o == e {
-			found = true
-			break
-		}
-	}
-	if !found {
-		t.Errorf("Can't find %q in output files.\nAll outputs:%v", e, outputs)
-	}
-
-	// Check the certificate paths
-	signapk := foo.Output("foo.apk")
-	signFlags := signapk.Args["certificates"]
-	e = "cert/new_cert.x509.pem cert/new_cert.pk8"
-	if e != signFlags {
-		t.Errorf("Incorrect signing flags, expected: %q, got: %q", e, signFlags)
-	}
-
-	// Check the manifest package name
-	res := foo.Output("package-res.apk")
-	aapt2Flags := res.Args["flags"]
-	e = "--rename-manifest-package org.dandroid.bp"
-	if !strings.Contains(aapt2Flags, e) {
-		t.Errorf("package renaming flag, %q is missing in aapt2 link flags, %q", e, aapt2Flags)
-	}
-}
diff --git a/java/java_test.go b/java/java_test.go
index bbcc9ed..8d3efcb 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -81,13 +81,11 @@
 	ctx.RegisterModuleType("droiddoc_host", android.ModuleFactoryAdaptor(DroiddocHostFactory))
 	ctx.RegisterModuleType("droiddoc_template", android.ModuleFactoryAdaptor(ExportedDroiddocDirFactory))
 	ctx.RegisterModuleType("java_sdk_library", android.ModuleFactoryAdaptor(SdkLibraryFactory))
-	ctx.RegisterModuleType("override_module", android.ModuleFactoryAdaptor(android.OverrideModuleFactory))
 	ctx.RegisterModuleType("prebuilt_apis", android.ModuleFactoryAdaptor(PrebuiltApisFactory))
 	ctx.PreArchMutators(android.RegisterPrebuiltsPreArchMutators)
 	ctx.PreArchMutators(android.RegisterPrebuiltsPostDepsMutators)
 	ctx.PreArchMutators(android.RegisterDefaultsPreArchMutators)
 	ctx.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.TopDown("load_hooks", android.LoadHookMutator).Parallel()
 		ctx.TopDown("prebuilt_apis", PrebuiltApisMutator).Parallel()
 		ctx.TopDown("java_sdk_library", SdkLibraryMutator).Parallel()
 	})