[Feature Request] Customize the dex --min-api

[liplum]

The default --min-api is 14, although Mindustry can run on Android 4.0.1 which is the minimum.
But in some rare cases, we need the """new""" features from higher version.

[liplum]

Since mgpp v1.1.1, you can

• Kotlin DSL

  tasks.dexJar {
      options.minApi = "26"
      options {
          minApi = "14"
      }
  }

• Groovy DSL

  dexJar {
      options.minApi = '26'
      options {
          minApi = '14'
      }
  }