Silence auto-value warning

com.google.auto.value.extension.memoized.MemoizeExtension depends
on javax.annotation.Generated, which is not visible by default in
OpenJDK9.  Expose the java.xml.ws.annotation module.

Fixes:
[ 65% 20175/31029] //external/turbine:turbine javac [linux_glibc common]
warning: An exception occurred while looking for AutoValue extensions. No extensions will function. This may be due to a corrupt jar file in the compiler's classpath. Exception: java.util.ServiceConfigurationError: com.google.auto.value.extension.AutoValueExtension: Provider com.google.auto.value.extension.memoized.MemoizeExtension could not be instantiated
1 warning

Bug: 62050818
Change-Id: If0b953dba477bb13bb2de90412a52bde80cb6316
Fixes: 123825567
Test: m turbine
diff --git a/Android.bp b/Android.bp
index e6006ea..c60243a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -29,6 +29,8 @@
         "jsr305-3.0.1",
     ],
 
+    // Required for use of javax.annotation.Generated per http://b/62050818
+    javacflags: ["-J--add-modules=java.xml.ws.annotation"],
     plugins: ["dagger2-auto-value"],
     libs: ["dagger2-auto-value"],