Remove android_prebuilt_sdk modules

Forcing sdk modules to be declared explicitly is unnecessary, just
add the required dependencies on the jar and aidl files.

Test: java_test.go
Change-Id: Ib28bdc1051c5825e7c0efb6adff1f9282675560e
diff --git a/android/config.go b/android/config.go
index f30a708..a70fa76 100644
--- a/android/config.go
+++ b/android/config.go
@@ -462,6 +462,10 @@
 	return Bool(c.ProductVariables.Allow_missing_dependencies)
 }
 
+func (c *config) UnbundledBuild() bool {
+	return Bool(c.ProductVariables.Unbundled_build)
+}
+
 func (c *config) DevicePrefer32BitExecutables() bool {
 	return Bool(c.ProductVariables.DevicePrefer32BitExecutables)
 }