Copy the Proguard mapping.txt next to the apk with a matching name

gistfile1.groovy

android.applicationVariants.all { variant ->

	if (variant.buildType.runProguard) {
		variant.assemble.doLast {
			description "ProGuard mapping copy"
			def mappingSource = new File(projectDir, "build/proguard/" + variant.buildType.name+"/mapping.txt")
			def mappingDest = new File(variant.outputFile.parent)
			copy {
				from mappingSource
				into mappingDest
				rename { String fileName ->
					fileName.replace('mapping.txt', variant.outputFile.name.replace(".apk", "-mapping.txt"))
				}
			}
		}
	}
}