Issue with '..android/deploy-test/release-prep/index.md' stating ProGuard as an obfuscation tool

[ciarancolgan]

Can't submit as PR as this line needs re-written by someone who knows the ProGuard tool better than me.

Page: https://github.com/MicrosoftDocs/xamarin-docs/blob/live/docs/android/deploy-test/release-prep/index.md

Line with issue: ProGuard is an Android SDK tool that links and obfuscates Java code.

Issue: ProGuard does not obfuscate Java code. It says this later in the same document: The Xamarin.Android ProGuard configuration does not obfuscate the APK, and it is not possible to enable obfuscation, even with custom configuration files

Solution: Re-write first line to not mention obfuscation