1-keep @interface android.annotation.SystemApi
2-keep @android.annotation.SystemApi public class * {
3    public protected *;
4}
5-keepclasseswithmembers public class * {
6    @android.annotation.SystemApi public protected <fields>;
7}
8-keepclasseswithmembers public class * {
9    @android.annotation.SystemApi public protected <init>(...);
10}
11-keepclasseswithmembers public class * {
12    @android.annotation.SystemApi public protected <methods>;
13}
14