RNCWebViewModule.java:276: error: cannot find symbol code example

Example: RNCWebViewModule.java:276: error: cannot find symbol

ext {
        buildToolsVersion = "28.0.3"
        minSdkVersion = 16
        compileSdkVersion = 29 // change from 28 -> 29
        targetSdkVersion = 29 // change from 28 -> 29
    }