Update CameraStreamBuffering test and correct instance name

- CameraStreamBuffering test is modified to use the minimum number of
  frame buffers that is required to run a camera pipeline for a single
  client instead of using an arbitrarily chosen number, which may not
  work for certain device implementations.
- Fix a name of v1.0 EvsManager implementation in
  VtsHalEvsV1_0TargetTest.cpp

Bug: 305642713
Test: atest VtsHalEvsV1_0TargetTest and
      atest VtsHalEvsV1_1TargetTest
Change-Id: Ieec986dbdf947311e0bc86871432da8a988d37ad
(cherry picked from commit 2d8834dc)