drone inject android signing

.drone.yml

@@ -60,10 +60,19 @@ steps:
 
   - name: build-android
     image: cirrusci/flutter:dev
+    when:
+      event: push
+    environment:
+      upload_jks_file:
+        from_secret: upload_jks_file
+      upload_jks_pass:
+        from_secret: upload_jks_pass
     volumes:
       - name: deps
         path: /root/.pub-cache
     commands:
+      - echo $upload_jks_file > upload-keystore.jks
+      - sed -i "s/%jks-password%/$upload_jks_pass/g" android/key.properties
       - flutter build appbundle
       # cant do debug for final release, this is just a stop gap
       - flutter build apk --debug