Removing Log call using proguard

You shouldn’t specify the ‘*’ wildcard, because that includes methods like ‘Object#wait()’. Better explicitly list the methods:

-assumenosideeffects class android.util.Log {
    public static boolean isLoggable(java.lang.String, int);
    public static int v(...);
    public static int i(...);
    public static int w(...);
    public static int d(...);
    public static int e(...);
}

This option is only relevant if optimization is not disabled, like in proguard-android.txt. You have to specify proguard-android-optimize.txt instead:

proguard.config=${sdk.dir}/tools/proguard/proguard-android-optimize.txt:proguard-project.txt

or with the contemporary Android Gradle plugin

buildTypes {
    releaseSomeBuildType {
        ...
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'your-proguard-file.pro'
    }
}