Refactor Bundle for thread-safety of Bundle.hasFileDescriptors()

After aosp/1878338, I realized Bundle.hasFileDescriptors() was accessing
mParcelledData and mMap without a lock. So, to avoid locking
there, I made mParcelledData volatile (since after mParcelledData is
null, it can never be non-null again and mMap is guaranteed to be
non-null). So, moved assignments to mParcelledData to be last wrt mMap
and mParcelledByNative to ensure visibility of those fields.

While refactoring copyInternal(), realized that method was always used
after constructing an uninitialized Bundle, so to avoid mistakes with
objects not properly initialized, I created a constructor in Bundle,
PersistableBundle & BaseBundle that does that copyInternal() did.

Bug: 195622897
Test: atest -d android.os.cts.ParcelTest android.os.cts.BundleTest android.os.BundleTest android.os.ParcelTest
Change-Id: I5c9337496da7ecf87f10370726099dcb247a6789