Upgrade gradle to ^5.4.1

[edlman]

Hello, I reopened few months old project where I use geolocation and streams_channel libs, updated flutter and all dependencies. I got an error during build saying I have to upgrade gradle from 4.10.2 to 5.4.1, so I changed it and project was built succesfully. Please update your streams_channel-0.3.0/android/gradle/wrapper/gradle-wrapper.properties to this distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip