[Android] 코틀린 imageView 동적추가

<동적으로 imageView 추가>
https://gihyun.com/62

<imageView size dp로 설정하기>
https://leesh217.tistory.com/entry/LayoutParams%EC%97%90%EC%84%9C-dp-%EB%8B%A8%EC%9C%84-%EC%93%B0%EA%B8%B0

<동적으로 margin 주기>
https://creon.tistory.com/440

<동적으로 gravity 설정>
https://rerethink.tistory.com/entry/%EC%95%88%EB%93%9C%EB%A1%9C%EC%9D%B4%EB%93%9C-%EC%BD%94%EB%93%9C%EC%97%90%EC%84%9C-LayoutParams-%EB%A5%BC-%EC%9D%B4%EC%9A%A9%ED%95%98%EC%97%AC-Gravity-%EC%A3%BC%EA%B8%B0

<동적으로 layout gravity 설정>

val layout = findViewById<LinearLayout>(R.id.layout_scrollView)
            val layoutParams = FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.WRAP_CONTENT)
            layoutParams.gravity = Gravity.CENTER
            layout.layoutParams = layoutParams