Remove unnecessary libnavigation-core Proguard rules

[Guardiola31337]

Tailwork from #2843

mapbox-navigation-android/libnavigation-core/proguard-rules.pro

Lines 9 to 10 in a361e6b

	# TODO Remove this rule when added in com.mapbox.common:logger https://github.com/mapbox/mapbox-base-android/issues/41
	-keep class com.mapbox.common.logger.MapboxLogger {*;}

Remove unnecessary Proguard rules from libnavigation-core/proguard-rules.pro when added downstream in com.mapbox.common:logger mapbox/mapbox-base-android#41

cc @RingerJK @LukasPaczos