aconfig: rename namespace -> package

What used to be referred to as a namespace is now called a package.

This CL is a semantic change only.

Bug: 285000854
Test: m nothing
Test: atest aconfig.test
Change-Id: If3fca67c415af75b44f316e16666b97089407069
diff --git a/tools/aconfig/templates/java.template b/tools/aconfig/templates/java.template
index 30c7ad7..44c470c 100644
--- a/tools/aconfig/templates/java.template
+++ b/tools/aconfig/templates/java.template
@@ -1,4 +1,4 @@
-package aconfig.{namespace};
+package aconfig.{package};
 {{ if readwrite }}
 import android.provider.DeviceConfig;
 {{ endif }}
@@ -7,7 +7,7 @@
     public static boolean {item.method_name}() \{
         {{ if item.readwrite- }}
         return DeviceConfig.getBoolean(
-            "{namespace}",
+            "{package}",
             "{item.feature_name}__{item.flag_name}",
             {item.default_value}
         );