ci(dependabot): add jitpack registry for gradle (#408)

.github/dependabot.yml

@@ -1,4 +1,18 @@
 version: 2
+
+registries:
+  maven-google:
+    type: maven-repository
+    url: "https://dl.google.com/dl/android/maven2/"
+
+  maven-central:
+    type: maven-repository
+    url: "https://repo.maven.apache.org/maven2"
+
+  jitpack:
+    type: maven-repository
+    url: "https://jitpack.io"
+
 updates:
   - package-ecosystem: "bundler"
     directory: "/"
@@ -13,6 +27,10 @@ updates:
 
   - package-ecosystem: "gradle"
     directory: "/"
+    registries:
+      - maven-central
+      - maven-google
+      - jitpack
     schedule:
       interval: "weekly"
     commit-message: