I first tried with invalidate cache/ restart option but it doesn't help me.
When I updated Kotlin to 1.1.60 in project's gradle file, problem is solved.
Also, use this in app's gradle for stdlib
implementation "org.jetbrains.kotlin:kotlin-stdlib:1.1.60"
instead of
implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:1.1.60"