Allow defaults in java_genrule modules

Call InitDefaultableModule in java_genrule factories to allow
the defaults property to be used.

Bug: 202547639
Test: m checkbuild
Change-Id: I3a5960304af3e9babb30d036d63016087000d773
diff --git a/java/genrule.go b/java/genrule.go
index e0a9c8f..16743b3 100644
--- a/java/genrule.go
+++ b/java/genrule.go
@@ -64,6 +64,7 @@
 	module := genrule.NewGenRule()
 
 	android.InitAndroidArchModule(module, android.HostAndDeviceSupported, android.MultilibCommon)
+	android.InitDefaultableModule(module)
 
 	return module
 }
@@ -76,6 +77,7 @@
 	module := genrule.NewGenRule()
 
 	android.InitAndroidArchModule(module, android.HostSupported, android.MultilibCommon)
+	android.InitDefaultableModule(module)
 
 	return module
 }