Android project not obfuscating

I want to obfuscate my android code, I have set minifienable true and setup proguard file, but after generating apk and decompile, the code is not obfuscated. This is my proguard :

my proguard file:

-dontwarn com.huawei.**
-dontwarn org.conscrypt.*
-dontwarn org.openjsse.javax.net.ssl.*
-dontwarn org.openjsse.net.ssl.OpenJSSE

my build.gradle file

    buildTypes {
        release {
            minifyEnabled true
            shrinkResources true
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }

        debug{
            minifyEnabled true
            shrinkResources true
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }

    }

from Android project not obfuscating