kotlin-stdlib-jre7 is deprecated. Please use kotlin-stdlib-jdk7 instead

Go to Tools > Kotlin > Configure Kotlin Plugin Updates and check for updates
then in your app gradle file replace jre with jdk

implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

Update

Newer version is jdk8

implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"