Stop ignoring the targetSdkVersion when it includes the API fingerprint SHA

Change https://r.android.com/1959021 introduced a regression in the
handling of the `targetSdkVersion` when using the API fingerprint.
Prior to that change, when `UseApiFingerprint(ctx)` returned true that
would cause all APKs (apart from `framework-res`) that were built to
use a `targetSdkVersion` that included the API fingerprint SHA. After
that change the `UseApiFingerprint(ctx)` had no effect on the setting
of `targetSdkVersion`.

This change corrects that.

Bug: 266899206
Test: UNBUNDLED_BUILD_SDKS_FROM_SOURCE=true UNBUNDLED_BUILD_TARGET_SDK_WITH_API_FINGERPRINT=true TARGET_BUILD_APPS="NetworkStack" m
      aapt2 dump badging out/target/product/generic/system/priv-app/NetworkStack/NetworkStack.apk
      # Run above before and after this change and see that the targetSdkVersion
      # has changed to `UpsideDownCake.<SHA>`.
Change-Id: Ic6e1da552c565cc4bd75cc734b3acb7faec67981