Separate rootVisited metrics into 2 categories

...for file managers and file pickers respectively.

Test: Automatic tests pass. Smoke manual tests.

Bug: 34157898
Change-Id: Iad861fff1a5fdebaa2ad6742ef3bb26d60df70b6
(cherry picked from commit 045ce6bc82a5a10dfcaf462481c4643b68ab343c)
3 files changed