Allow access to the generated srcjars for GeneratedJavaLibrary

Bug: 293195086
Test: m
Change-Id: I42cf0238241314376f5fe0091cde9bef196f4b9d
diff --git a/java/base.go b/java/base.go
index a9b986b..4fe093a 100644
--- a/java/base.go
+++ b/java/base.go
@@ -622,6 +622,8 @@
 			return android.Paths{j.dexer.proguardDictionary.Path()}, nil
 		}
 		return nil, fmt.Errorf("%q was requested, but no output file was found.", tag)
+	case ".generated_srcjars":
+		return j.properties.Generated_srcjars, nil
 	default:
 		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
 	}