Autogen python test config.

Feature request from developer, autogen python test config.

Bug:118442443

Test: $source build/envsetup.sh ; lunch
      $sed -i '/test_config/d' tools/acloud/Android.bp
      $make acloud_test
      $[ -f $ANDROID_HOST_OUT_TESTCASES/acloud_test/acloud_test.config ] && echo "Found" || echo "Not found"

Change-Id: I196230581b456afe03e67f9cd84c028d18ba08d9

python/androidmk.go

@@ -70,6 +70,11 @@ func (p *testDecorator) AndroidMk(base *Module, ret *android.AndroidMkData) {
 		if p.testProperties.Test_config != nil {
 			fmt.Fprintln(w, "LOCAL_TEST_CONFIG :=",
 				*p.testProperties.Test_config)
+		} else {
+			if p.testConfig != nil {
+				fmt.Fprintln(w, "LOCAL_FULL_TEST_CONFIG :=",
+					p.testConfig.String())
+			}
 		}
 	})
 	base.subAndroidMk(ret, p.binaryDecorator.pythonInstaller)