chore: improve travis build for android

.travis.yml

@@ -9,7 +9,6 @@ matrix:
   include:
     - name: "iOS Build & Test"
       language: objective-c
-      sudo: false
       os: osx
       osx_image: xcode12.5
 
@@ -29,11 +28,15 @@ matrix:
 
     - name: "Android Build & Test"
       language: android
-      sudo: required
 
-      android:
-        components:
-          - tools
+      before_cache:
+        - rm -f $HOME/.gradle/caches/modules-2/modules-2.lock
+        - rm -rf $HOME/.gradle/caches/*/plugin-resolution/
+
+      cache:
+        directories:
+          - $HOME/.gradle/caches/
+          - $HOME/.gradle/wrapper/
 
       before_install:
         - export LANG=en_US.UTF-8 &&