Avoid full unparcelling where possible in Bundle

and put a warning where it's not possible. This is to make sure we know
when to touch bundles provided by apps.

In this CL:
* deepCopy() now doesn't deserialize lazy objects before copying. It
  doesn't copy them either, it merely passes them into the new map as
  the same reference. This works because we implemented fine-grained
  locking into each lazy value, so concurrent access won't be a problem.
  Furthermore, LazyValue caches the deserialized object, so we'd still
  honor the contract of deepCopy() that "Other types of objects (such
  as Parcelable or Serializable) are referenced as-is and not copied in
  any way". I had to perform one extra check in the synchronized block
  in LazyValue to guarantee this (double-checked locking), I explain
  that in the comments.
* Removed filterValues() and codepaths that used it. This was created
  with the purpose of removing items whose classes weren't available to
  the system to prevent crashes coming from full deserialization. This
  is not a concern anymore with lazy bundle, hence we can remove the
  codepaths altogether (see email for more details).
* Put warnings in javadoc of getMap() and PeristableBundle().

Test: Boots
Test: atest -d android.os.cts.ParcelTest android.os.cts.BundleTest android.os.BundleTest android.os.ParcelTest
Bug: 195622897
Change-Id: I14bb6a7874814f42cbcc6b5fd372c42752aa74c8