Allow test to specify whether or not to auto-generate test config

Attribute `auto_gen_config` is added to test modules.
Test config will be generated if:
the attribute is not set and AndroidTest.xml doesn't exists
or
the attribute is set to true, whether or not AndroidTest.xml exists.

Test config will NOT be auto-generated if:
the attribute is not set and AndroidTest.xml exists
or
the attribute is set to false, whether or not AndroidTest.xml exists.

Bug: 141684102
Test: build test module with auto_gen_config set to true
Change-Id: I64fb003a83d8c32a967835e5f8d12fe4476043be
diff --git a/java/java.go b/java/java.go
index 4dd6a49..ce72c27 100644
--- a/java/java.go
+++ b/java/java.go
@@ -1685,6 +1685,11 @@
 	// list of files or filegroup modules that provide data that should be installed alongside
 	// the test
 	Data []string `android:"path"`
+
+	// Flag to indicate whether or not to create test config automatically. If AndroidTest.xml
+	// doesn't exist next to the Android.bp, this attribute doesn't need to be set to true
+	// explicitly.
+	Auto_gen_config *bool
 }
 
 type testHelperLibraryProperties struct {
@@ -1709,7 +1714,8 @@
 }
 
 func (j *Test) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	j.testConfig = tradefed.AutoGenJavaTestConfig(ctx, j.testProperties.Test_config, j.testProperties.Test_config_template, j.testProperties.Test_suites)
+	j.testConfig = tradefed.AutoGenJavaTestConfig(ctx, j.testProperties.Test_config, j.testProperties.Test_config_template,
+		j.testProperties.Test_suites, j.testProperties.Auto_gen_config)
 	j.data = android.PathsForModuleSrc(ctx, j.testProperties.Data)
 
 	j.Library.GenerateAndroidBuildActions(ctx)