Add DexFileContainer for all DexFiles.

Ensure that all DexFiles have a container for consistency.

Enforce that the container shall contain exactly one dex file,
as specified the by file_size entry in the de header
(that is, the memory range should not be truncated or too big).

Bug: 266950186
Test: test.py -b --host --optimizing --64
Change-Id: I73ff074a980f9a9d5a0f4a9b51ac1a496971374f