Set version code of apex and apk based on RELEASE_DEFAULT_UPDATABLE_MODULE_VERSION.

The build flag RELEASE_DEFAULT_UPDATABLE_MODULE_VERSION is set up to
allow the default version code of updatable apk and apex to be
configurable per release config. Use the value from flag and remove old constant value (DefaultUpdatableModuleVersion).

Bug: 369531931
Test: presubmit
Test: flash cf and check version
Change-Id: Ia0a8634360cbe83501cdafee888678836005620f