Gradle: exclude something from AndroidManifest.xml by regexp, then use Proguard to throw it away

AndroidManifest.xml

<!-- START: XXX Do not remove the comment's START-END pair. Used by Gradle -->
        ...
<!-- END: XXX -->

build.gradle

import java.util.regex.Pattern
android {
applicationVariants.all { variant ->
        variant.outputs.each { output ->
            if (variant.getBuildType().isMinifyEnabled()) {
                output.processManifest.doFirst {

                    copy {
                        from "${rootDir}/<project name>/src/main/AndroidManifest.xml"
                        into "${rootDir}/<project name>/src/main"
						rename { String fileName ->
                            "AndroidManifest.xml.bak"
                        }
                    }

                    def manifestFile = file("${rootDir}/<project name>/src/main/AndroidManifest.xml")
                    def content = manifestFile.getText()

                    def pattern = Pattern.compile("<!-- START: XXX.*?<!-- END: XXX -->", Pattern.DOTALL);
                    content = pattern.matcher(content).replaceAll("");

                    manifestFile.write(content)
                }

                output.processManifest.doLast {
				copy {
                        from "${rootDir}/<project name>/src/main/AndroidManifest.xml.bak"
                        into "${rootDir}/<project name>/src/main"
						rename { String fileName ->
                            "AndroidManifest.xml"
                        }
                    }
					delete "${rootDir}/<project name>/src/main/AndroidManifest.xml.bak"
				}
            }
        }

}

Based on Modifying AndroidManifest.xml file per product using Gradle