aconfig: Add codegen for java

Add codegen for java skeleton

Bug: 279485059
Test: atest aconfig.test
Change-Id: Ia0481cec9c2e137e88e9a77d1b82412529b64adc
diff --git a/tools/aconfig/templates/java.template b/tools/aconfig/templates/java.template
new file mode 100644
index 0000000..3854579
--- /dev/null
+++ b/tools/aconfig/templates/java.template
@@ -0,0 +1,19 @@
+package com.android.aconfig;
+{{ if readwrite }}
+import android.provider.DeviceConfig;
+{{ endif }}
+public final class {namespace} \{
+    {{ for item in class_elements}}
+    public static boolean {item.method_name}() \{
+        {{ if item.readwrite- }}
+        return DeviceConfig.getBoolean(
+            "{namespace}",
+            "{item.feature_name}__{item.flag_name}",
+            {item.default_value}
+        ); 
+        {{ -else- }}
+        return {item.default_value};
+        {{ -endif }}
+    }
+    {{ endfor }}
+}