Unable to change widget size using wrap_content on Android Studio

It may have been a while since your question was asked, but it is recommended that you read the official documentation after you have tried the tutorial.

https://developer.android.com/training/basics/firstapp?hl=ja
https://developer.android.com/guide/topics/ui/declaring-layout?hl=ja

Basically, Android screen layout is represented by layout and widget nesting.Android apps run on multiple devices and screen orientation, so it is recommended that the widget be automatically positioned and sized accordingly.(ConstraintLayout is now recommended in recent updates)

• If width, hegith is omitted from the widget, the default size is 0 for both
  'wrap_content' means to automatically resize the element based on what it contains.For example, if an image is included, it will be automatically adjusted to that size.
• LinearLayout has a linear placement.Lists the included widgets according to the specified orientation.This makes it difficult to work with an android-studio editor.By nature, width and height are typically wrap_content.
• Include widgets in AbsoluteLayout to specify an absolute value.However, this element is deprecated.

In the end, XML operations will be easier, so it is recommended that the layout be textual.