Set targetSdkVersion to 10000 iff a module is targeting an unreleased

sdk

Previously in aosp/1907152, targetSdkVersion for all modules would be
10000 in release builds. This would cause sdk compatibility errors like
b/209301265#3 for modules that were targeting a released SDK

This CL adds an additional check to set targetSdkVersion to 10000 only
if a module's apilevel is in preview (i.e. unreleased SDK)

Bug: 209301265

Test: Built various apk combinations locally, and used aapt2 to check
targetSdkVersion
Test: TARGET_BUILD_APPS=xyz m CaptivePortalLoginTests #
targetSdkVersion: 30
Test: m CaptivePortalLoginTests #targetSdkVersion: 30
Test: (internal) TARGET_BUILD_APPS=xyz m MediaProviderGoogle #
targetSdkVersion: 10000
Test: (internal) m MediaProviderGoogle #targetSdkVersion: Tiramisu

Change-Id: Id2901f23d4e1b436f8906940e47edd606a93657d