Update patch that unlocks the pro version

Extracted patch application into dedicated RUN step so we end up with an
image right before patches are applied, which is conventient to debug.

Dockerfile

@@ -28,8 +28,9 @@ ARG KEYSTORE_PROPERTIES
 RUN curl -OL https://github.com/M66B/FairEmail/archive/$VERSION.tar.gz \
     && tar xvzf $VERSION.tar.gz \
     && cd FairEmail-$VERSION \
-    && (for patch in /patches/*; do patch -p0 < $patch; done) \
     && echo $KEYSTORE_FILE | base64 -d > keystore.jks \
-    && echo $KEYSTORE_PROPERTIES | base64 -d > keystore.properties \
+    && echo $KEYSTORE_PROPERTIES | base64 -d > keystore.properties
-    && gradle --no-daemon assemble \
+RUN cd FairEmail-$VERSION \
-    && cp app/build/outputs/apk/full/github/FairEmail-v$VERSION-full-github.apk /apk
+    && (for patch in /patches/*; do patch -p0 < $patch; done) \
+    && gradle --no-daemon assemble
+RUN cp FairEmail-$VERSION/app/build/outputs/apk/github/release/FairEmail-v$VERSION-github-release.apk /apk

patches/10-pro.diff

@@ -1,12 +1,13 @@
---- app/src/main/java/eu/faircode/email/ActivityBilling.java	2020-04-11 09:27:44.000000000 +0000
+--- app/src/play/java/eu/faircode/email/ActivityBilling.java	2020-08-15 10:33:56.000000000 +0000
-+++ app/src/main/java/eu/faircode/email/ActivityBilling.java	2020-04-11 09:27:44.000000000 +0000
++++ app/src/play/java/eu/faircode/email/ActivityBilling.java	2020-08-15 10:33:56.000000000 +0000
-@@ -192,9 +192,7 @@
+@@ -192,10 +192,7 @@
      }
  
      static boolean isPro(Context context) {
 -        if (BuildConfig.DEBUG && false)
 -            return true;
--        return PreferenceManager.getDefaultSharedPreferences(context).getBoolean("pro", false);
+-        return PreferenceManager.getDefaultSharedPreferences(context)
+-                .getBoolean("pro", false);
 +        return true;
      }