increase the minSdkVersion to 26

AGPBI: {"kind":"error","text":"Invoke-customs are only supported starting with Android O (--min-api 26)","sources":[{}],"tool":"D8"}
> Task :app:mergeExtDexDebug
> Task :app:transformClassesWithDexBuilderForDebug
> Task :app:mergeDexDebug FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:mergeDexDebug'.
> Could not resolve all files for configuration ':app:debugRuntimeClasspath'.
> Failed to transform artifact 'full.jar (project :extras:XCloud_Framework_Library)' to match attributes {artifactType=android-dex, com.android.build.api.attributes.BuildTypeAttr=debug, com.android.build.api.attributes.VariantAttr=debug, com.android.build.gradle.internal.dependency.AndroidTypeAttr=Aar, dexing-is-debuggable=true, dexing-min-sdk=14, org.gradle.usage=java-runtime}
> Execution failed for DexingTransform: /Users/XXX/Android/workspace/XCIntellectCloudPlatform_N/extras/XCloud_Framework_Library/build/intermediates/full_jar/debug/createFullJarDebug/full.jar.
> Error while dexing.
The dependency contains Java 8 bytecode. Please enable desugaring by adding the following to build.gradle
android {
compileOptions {
sourceCompatibility 1.8
targetCompatibility 1.8
}
}
See https://developer.android.com/studio/write/java8-support.html for details. Alternatively, increase the minSdkVersion to 26 or above.