Added android test in travis ci

Author: gauravk95

.travis.yml

@@ -12,10 +12,13 @@ android:
     - build-tools-27.0.3
     - android-27
     - extra-android-m2repository
-    - sys-img-armeabi-v7a-android-26
 
   licenses:
     - android-sdk-license-.+
 
-  script:
-    ./gradlew clean build
+  # Emulator Management: Create, Start and Wait
+  before_script:
+    - echo no | android create avd --force -n test -t android-22 --abi armeabi-v7a
+    - emulator -avd test -no-audio -no-window &
+    - android-wait-for-emulator
+    - adb shell input keyevent 82 &