Increase Gradle heap for Android release builds (#76)

Author: Pygmalion69

gradle.properties

@@ -6,7 +6,10 @@
 # http://www.gradle.org/docs/current/userguide/build_environment.html
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-org.gradle.jvmargs=-Xmx1536m
+# D8 and Android lint run during release packaging and exceed the default heap on
+# this project's dependency graph. Keep enough headroom for both in the Gradle
+# daemon rather than failing during dex archive merging.
+org.gradle.jvmargs=-Xmx4g
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects