Use protoc-gen-javalite for java lite protos

Protobuf 3.5.2 does not natively support lite protos, instead they
are generated by the protoc-gen-javalite plugin compiled from
external/protobuf-javalite.

Bug: 117607748
Test: m checkbuild
Change-Id: I95c2d873f19d4c00e9dc312d7fdbe98cae250a8b
diff --git a/android/config.go b/android/config.go
index 695a298..cca1c7a 100644
--- a/android/config.go
+++ b/android/config.go
@@ -351,6 +351,10 @@
 
 var _ bootstrap.ConfigBlueprintToolLocation = (*config)(nil)
 
+func (c *config) HostToolPath(ctx PathContext, tool string) Path {
+	return PathForOutput(ctx, "host", c.PrebuiltOS(), "bin", tool)
+}
+
 // HostSystemTool looks for non-hermetic tools from the system we're running on.
 // Generally shouldn't be used, but useful to find the XCode SDK, etc.
 func (c *config) HostSystemTool(name string) string {