Update ProGuard Rules for API 101

[DavidBerdik]

The proguard-rules.pro file in this sample project appears to still be using rules intended for API 100. I would really appreciate it if the rules could be updated for API 101!

For the LSPosed module that I updated to API 101, I modified the Xposed block of the file to this:

# Xposed
-adaptresourcefilecontents META-INF/xposed/java_init.list
-keepattributes RuntimeVisibleAnnotations
-keep,allowobfuscation,allowoptimization public class * extends io.github.libxposed.api.XposedModule {
    public <init>(...);
    public void onModuleLoaded(...);
    public void onPackageLoaded(...);
    public void onPackageReady(...);
    public void onSystemServerStarting(...);
}

This seems to work, but even so, it would be very useful to have a reference implementation to check against.