Add support for using sdk_version: "module_<ver>"

Fixes a panic when trying to build something with
sdk_version: "module_30".

Change-Id: I5b625eee45130cc288e3082d05fe45c9d006d0b6
Test: m nothing
Merged-In: I9b2ce50957f59e2bead335ffa58888e15cda1f78
diff --git a/java/sdk.go b/java/sdk.go
index 6c16651..5a6c530 100644
--- a/java/sdk.go
+++ b/java/sdk.go
@@ -215,7 +215,7 @@
 		return ctx.Config().UnbundledBuildUsePrebuiltSdks()
 	} else if s.version.isNumbered() {
 		// sanity check
-		if s.kind != sdkPublic && s.kind != sdkSystem && s.kind != sdkTest {
+		if s.kind != sdkPublic && s.kind != sdkSystem && s.kind != sdkTest && s.kind != sdkModule {
 			panic(fmt.Errorf("prebuilt SDK is not not available for sdkKind=%q", s.kind))
 			return false
 		}