Camera: Handle duplicate camera Id due to openLegacy support

When HAL supports openLegacy, same camera id can be added more than
once.

Because we now use vector to store API1 compatible camera ids, make
sure no duplicate strings are added.

Test: Vendor camera app using openLegacy, Camera CTS
Bug: 110815837
Bug: 111963599

Change-Id: I327744e102cc75929ebcdf51661f9f4ec7f3acf9
Merged-In: I327744e102cc75929ebcdf51661f9f4ec7f3acf9
(cherry picked from commit 975a39e9)
(cherry picked from commit 258fa266)