[drawable-xhdpi-v4]png: Error: Duplicate resources

解决办法：
https://stackoverflow.com/questions/53239705/react-native-error-duplicate-resources-android

找到node_modules/react-native/react.gradle，
在doFirst后面加上如下代码，如下：

			doFirst {
                jsBundleDir.deleteDir()
                jsBundleDir.mkdirs()
                resourcesDir.deleteDir()
                resourcesDir.mkdirs()
            }
            doLast {
                def moveFunc = { resSuffix ->
                    File originalDir = file("$buildDir/generated/res/react/release/drawable-${resSuffix}");
                    if (originalDir.exists()) {
                        File destDir = file("$buildDir/../src/main/res/drawable-${resSuffix}");
                        ant.move(file: originalDir, tofile: destDir);
                    }
                }
                moveFunc.curry("ldpi").call()
                moveFunc.curry("mdpi").call()
                moveFunc.curry("hdpi").call()
                moveFunc.curry("xhdpi").call()
                moveFunc.curry("xxhdpi").call()
                moveFunc.curry("xxxhdpi").call()
            }