Don't try to sign APKs until deploy

This means we might not notice an signing issue normally,
until deploy time, but on the other hand it means that PRs
will build successfully, which is pretty useful!

Author: pimterry

.travis.yml

@@ -4,12 +4,12 @@ android:
   components:
   - build-tools-29.0.3
   - android-30
-before_install:
-- openssl aes-256-cbc -K $encrypted_410c058128c0_key -iv $encrypted_410c058128c0_iv
-  -in android-travis-cert-store.enc -out ./android-travis-cert-store.jks -d
 script:
 - yes | sdkmanager "platforms;android-30" # Accept the Android 11 platform license, since Travis can't yet
 - "./gradlew assembleRelease"
+before_deploy:
+- openssl aes-256-cbc -K $encrypted_410c058128c0_key -iv $encrypted_410c058128c0_iv
+  -in android-travis-cert-store.enc -out ./android-travis-cert-store.jks -d
 - jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -storepass $CERT_STORE_PWD
   -keypass $CERT_STORE_PWD -keystore ./android-travis-cert-store.jks app/build/outputs/apk/release/app-release-unsigned.apk
   $CERT_ALIAS