Remove custom appservices repository

Appservices artifacts are now being manually mirrored to m.m.o.
Eventually, they will be automatically published to m.m.o

build.gradle

@@ -24,9 +24,6 @@ plugins {
 allprojects {
     repositories {
         google()
-        maven {
-            url "https://dl.bintray.com/mozilla-appservices/application-services"
-        }
         maven {
             url "https://snapshots.maven.mozilla.org/maven2"
         }