feat: support custom compileSdk setting (#1431)

* feat: support custom compileSdk setting
* chore: apply suggestions from code review
* chore: apply cdv-gradle-config-defaults.json suggestion
* fix: set compile sdk when null
* fix: move compileSdk null check to gradle
* fix: compile sdk requirement warning & display in gradle per subproject

Co-authored-by: Norman Breau <norman@nbsolutions.ca>

templates/project/app/build.gradle

@@ -188,7 +188,7 @@ android {
             maxSdkVersion cordovaConfig.MAX_SDK_VERSION
         }
         targetSdkVersion cordovaConfig.SDK_VERSION
-        compileSdkVersion cordovaConfig.SDK_VERSION
+        compileSdkVersion cordovaConfig.COMPILE_SDK_VERSION
     }
 
     lintOptions {

templates/project/build.gradle

@@ -27,6 +27,8 @@ buildscript {
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
+
+    cdvHelpers.verifyCordovaConfigForBuild()
 }
 
 allprojects {