How can you resolve failed proguard transform of apk?

Question

I'm using Gradle in a react-native app to build a signed APK via - ./gradlew assembleRelease using this config:

        release {
            minifyEnabled enableProguardInReleaseBuilds
            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
        } 

But during assembling the apk I get the error summary:

 Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.

I see from the error that the app build fails due to a Proguard warning. I see other options for disabling proguard but I don't want to skip optimizing the code before building the Apk.

Question:

How can you resolve the failed pro guard transform of APK?

This is a gist of the failed grade task:

Note: there were 2 references to unknown classes.
      You should check your configuration for typos.
      (http://proguard.sourceforge.net/manual/troubleshooting.html#unknownclass)
Note: there were 658 unkept descriptor classes in kept class members.
      You should consider explicitly keeping the mentioned classes
      (using '-keep').
      (http://proguard.sourceforge.net/manual/troubleshooting.html#descriptorclass)
Note: there were 7 unresolved dynamic references to classes or interfaces.
      You should check if you need to specify additional program jars.
      (http://proguard.sourceforge.net/manual/troubleshooting.html#dynamicalclass)
Warning: there were 1 unresolved references to library class members.
         You probably need to update the library versions.
         (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedlibraryclassmember)

And the app/build.gradle file:

apply plugin: "com.android.application"

import com.android.build.OutputFile


apply from: "../../node_modules/react-native/react.gradle"

def enableSeparateBuildPerCPUArchitecture = true

def enableProguardInReleaseBuilds = true

android {
    useLibrary 'org.apache.http.legacy'    
    compileSdkVersion 23
    buildToolsVersion "25.0.0"

    defaultConfig {
        applicationId "com.simpleoffsetpro"
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        ndk {
            abiFilters "armeabi-v7a", "x86"
        }
    }
    splits {
        abi {
            reset()
            enable enableSeparateBuildPerCPUArchitecture
            universalApk false  // If true, also generate a universal APK
            include "armeabi-v7a", "x86"
        }
    }
    buildTypes {
        release {
            minifyEnabled enableProguardInReleaseBuilds
            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
        }
    }
    // applicationVariants are e.g. debug, release
    applicationVariants.all { variant ->
        variant.outputs.each { output ->
            // For each separate APK per architecture, set a unique version code as described here:
            // http://tools.android.com/tech-docs/new-build-system/user-guide/apk-splits
            def versionCodes = ["armeabi-v7a":1, "x86":2]
            def abi = output.getFilter(OutputFile.ABI)
            if (abi != null) {  // null for the universal-debug, universal-release variants
                output.versionCodeOverride =
                        versionCodes.get(abi) * 1048576 + defaultConfig.versionCode
            }
        }
    }
}

dependencies {
    compile project(':react-native-localization')
    compile project(':react-native-vector-icons')
    compile fileTree(dir: "libs", include: ["*.jar"])
    compile "com.android.support:appcompat-v7:25.0.1"
    compile "com.facebook.react:react-native:+"  // From node_modules
}

// Run this once to be able to run the application with BUCK
// puts all compile dependencies into folder libs for BUCK to use
task copyDownloadableDepsToLibs(type: Copy) {
  from configurations.compile
  into 'libs'
}