Target texture compression formats.
If you set multiple texture compression formats, you can use the Texture Compression Targeting feature. To use this feature you must also build the application as an Android App Bundle (aab file) or export a Gradle project for an Android App Bundle. In this case, Unity generates the Android App Bundle or the Gradle project with asset packs that include textures compressed using the texture compression formats you specify in this property. Android treats the first texture compression format as the "default".
If you only set one target texture compression format, or if you build your application as an apk or export Gradle project for an apk, Android only uses the first (or only) texture compression format to compress textures. In this case, you can override the target texture compression format using the EditorUserBuildSettings.androidBuildSubtarget property.
You can't add the TextureCompressionFormat.BPTC or TextureCompressionFormat.Unknown options to texture compression formats for Android, also it's not possible to assign a null value or an empty array.