Add maven publishing configuration for Godot tools

The Godot Android library on MavenCentral is a `template` build; this updated configuration adds a new 'Godot Tools' publishing artifact, allowing developers access to the `editor` build of the Godot Android library.

platform/android/java/lib/build.gradle

@@ -5,6 +5,7 @@ plugins {
 
 ext {
     PUBLISH_ARTIFACT_ID = 'godot'
+    TOOLS_PUBLISH_ARTIFACT_ID = 'godot-tools'
 }
 
 apply from: "../scripts/publish-module.gradle"
@@ -185,5 +186,9 @@ android {
             withSourcesJar()
             withJavadocJar()
         }
+        singleVariant("editorRelease") {
+            withSourcesJar()
+            withJavadocJar()
+        }
     }
 }