Add option to obfuscate debug builds

This is useful for UI tests to catch issues that doesn't happen in
not-minified builds.
Use `./gradlew -Pminify=true` to pass the argument to gradle.
At now we just check that the property is there (not the value)

MAILAND-1421

app/build.gradle.kts

@@ -147,7 +147,7 @@ android(appIdSuffix = "android") {
             multiDexKeepProguard = File("multidex-proguard.pro")
         }
         getByName("debug") {
-            isMinifyEnabled = false
+            isMinifyEnabled = project.hasProperty("minify")
             isTestCoverageEnabled = true
         }
         getByName("release") {