Suppress wjavac warnings when compiling proto lite generated code.

Bug:
Change-Id: I9978f59dd527bb013da1e7c8a08ad99e937ccadb
diff --git a/build.gradle b/build.gradle
index a00c516..db9f058 100644
--- a/build.gradle
+++ b/build.gradle
@@ -528,6 +528,10 @@
     dependsOn jar_debugTestResourcesJava8
 }
 
+// Proto lite generated code yields warnings when compiling with javac.
+// We change the options passed to javac to ignore it.
+compileExamplesJava.options.compilerArgs = ["-Xlint:none"]
+
 task buildExampleJars {
     dependsOn downloadProguard
     def examplesDir = file("src/test/examples")