ProGuard and R8 are tools used for obfuscation, optimization, shrinking, and minification. R8 is a more advanced and paid version of ProGuard.  GBG provides a ProGuard script (proguard-rules-mjcs.pro) in the sample app with info package. If your version of SDK is different from the sample app, please ask for an updated info pack.

ProGuard or R8 is obfuscation, optimization, shrinking and minification tool.

R8 https://r8.googlesource.com/r8/ 

ProGuard https://www.guardsquare.com/en/products/proguard

DexGuard ( Paid and more Advanced version of ProGuard) https://www.guardsquare.com/en/products/dexguard

This should work for DexGuard according to client feedback, however this has not been tested for official release.