After opening an old project with the latest updated android studio, I am having this error for the build.gradle file. What should I change?
Having error for the appcompact-v7 dependency: All com.android.support libraries must use the exact same version specification. Found version 26.1.0, 19.1.0.
apply plugin: 'com.android.application'
android {
compileSdkVersion 19
buildToolsVersion '27.0.3'
defaultConfig {
    applicationId "X"
    minSdkVersion 15
    targetSdkVersion 19
    versionCode 7
    versionName "name"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:19.1.0'
    compile 'com.google.android.gms:play-services-ads:12.0.1'
}
 
     
     
    