Change Firestore branch location (for TIP) to main.

Author: jonsimantov

cmake/external/firestore.cmake

@@ -68,7 +68,7 @@ if((NOT FIRESTORE_DEP_SOURCE) OR (FIRESTORE_DEP_SOURCE STREQUAL "RELEASED"))
  GetReleasedDep()
 else()
  if(FIRESTORE_DEP_SOURCE STREQUAL "TIP")
- GetTag("origin/master")
+ GetTag("origin/main")
  else()
  GetTag(${FIRESTORE_DEP_SOURCE})
  endif()