title: android.support.v7.widget.Toolbar was not found
body: <p>The build.gradle file at app level is given below</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'com.google.gms.google-services'
  
      android {
          compileSdkVersion 28
          buildToolsVersion "28.0.3"
          defaultConfig {
              applicationId "com.example.sscmessenger"
              minSdkVersion 19
              targetSdkVersion 28
              versionCode 1
              versionName "1.0"
              testInstrumentationRunner 
  "androidx.test.runner.AndroidJUnitRunner"
  }
  buildTypes {
      release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     //noinspection GradleCompatible
     implementation 'com.android.support:design:28.0.0-rc01'
     implementation 'com.android.support:support-v4:28.0.0-rc01'
     implementation 'com.firebaseui:firebase-ui-database:3.2.2'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     implementation 'com.google.firebase:firebase-auth:19.0.0'
     implementation 'com.google.firebase:firebase-database:19.0.0'
     testImplementation 'junit:junit:4.12'
     implementation 'com.android.support:appcompat-v7:28.0.3'
  
  
     }
  </code></pre>
  
  <blockquote>
    <p>Blockquote</p>
  </blockquote>