title: Adding support:preference-v7 or -v14 library causes Gradle build to fail
body: <p>My project builds fine, until I attempt to include the Support Preference library.</p>
  
  <p>When I do, build fails with this error:</p>
  
  <pre><code>C:\Users\user\.gradle\caches\transforms-1\files-1.1\appcompat-v7-27.0.0.aar\e8afe3ff4b4dc10495266439a3695e57\res\values\values.xml:252:5-69: AAPT: error: duplicate value for resource 'attr/min' with config ''.
  
  C:\Users\user\.gradle\caches\transforms-1\files-1.1\appcompat-v7-27.0.0.aar\e8afe3ff4b4dc10495266439a3695e57\res\values\values.xml:252:5-69: AAPT: error: resource previously defined here.
  
  C:\Users\user\StudioProjects\project\app\build\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:627: error: duplicate value for resource 'attr/min' with config ''.
  
  C:\Users\user\StudioProjects\project\app\build\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:483: error: resource previously defined here.
  
  * What went wrong:
  Execution failed for task ':app:mergeDebugResources'.
  &gt; Error: java.util.concurrent.ExecutionException: com.android.tools.aapt2.Aapt2Exception: AAPT2 error: check logs for details
  </code></pre>
  
  <p>I really don't know why this error is occuring...</p>
  
  <p>EDIT: Full build.gradle:</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'io.fabric'
  
  android {
      compileSdkVersion 27
  
      compileOptions { 
          sourceCompatibility JavaVersion.VERSION_1_8
          targetCompatibility JavaVersion.VERSION_1_8
      }
  
      defaultConfig {
          applicationId "com.myapp"
          minSdkVersion 16
          targetSdkVersion 27
          multiDexEnabled true
          versionCode 1
          versionName "myVersion" 
          resConfigs "en"
      }
  
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
  
          debug {
              ext.enableCrashlytics = false
          }
      }
  }
  
  dependencies {
      implementation fileTree(include: ['*.jar'], dir: 'libs')
  
      def firebaseVersion = '11.4.2'
      def supportVersion = '27.0.0'
  
      //Firebase Crashlytics
      compile('com.crashlytics.sdk.android:crashlytics:2.7.1@aar') {
          transitive = true
      }
  
      //Firebase
      implementation 'com.google.firebase:firebase-auth:' + firebaseVersion
      implementation 'com.google.firebase:firebase-core:' + firebaseVersion
      implementation 'com.google.firebase:firebase-firestore:' + firebaseVersion
  
      //FirebaseUI
      implementation 'com.firebaseui:firebase-ui-auth:3.1.0'
  
      //Android Support
      implementation 'com.android.support:support-v4:' + supportVersion
  
      implementation 'com.android.support:appcompat-v7:' + supportVersion
      implementation 'com.android.support:cardview-v7:' + supportVersion
      implementation 'com.android.support:gridlayout-v7:' + supportVersion
      implementation 'com.android.support:recyclerview-v7:' + supportVersion
      implementation 'com.android.support:preference-v7:' + supportVersion
  
      implementation 'com.android.support:preference-v14:' + supportVersion 
  
      implementation 'com.android.support:support-vector-drawable:' + supportVersion
  
      implementation 'com.android.support:design:' + supportVersion
  
      implementation 'com.android.support.constraint:constraint-layout:1.0.2'
  
      implementation 'com.android.support:multidex:1.0.2'
  
      //Material About
      implementation 'com.github.daniel-stoneuk:material-about-library:2.2.3-support26.1.0' //Weird version system
  
      //OpenCSV
      implementation('com.opencsv:opencsv:4.0') {
          //Transitively requires Apache Commons, which necessitates multidex...
          exclude group: 'commons-beanutils'
      }
  
      //Gson
      implementation 'com.google.code.gson:gson:2.8.2'
  }
  
  apply plugin: 'com.google.gms.google-services'
  </code></pre>
  
  <p>It wants some more details, so I'll elaborate on the problem.
  I want to use the AppCompat Preference library, but the error at the beginning pops up whenever I try to add it to my build.gradle. </p>