Replace shared_ptr with plain object

Currently most of objects are managed with shared_ptr. However, as these
objects are not being shared, it can be managed with plain object. To
make it simple, it would be better to remove all shared_ptr in use.

Bug: 123722631
Test: m -j & atest passed
Change-Id: I16fbf8bc63f016dc0603e1081164fbaabcb32d8e
37 files changed