[M123] Cherrypick: Add API for resetting the session.

Create `SessionController` abstract class where the session management
logic will be put in the future.

Modify the Tracker creation API to allow dependency injection of the session controller object, currently using a default implementation for all platforms.

Create public API `ResetSession` in condition validator and implement it in once_condition_validator.

Fix: b/324949376

(cherry picked from commit cb1f159a599a12581bebcb48a64e38662c134075)

Change-Id: I8abc90947c4a6b37563434a6796a4cfa81ea6262
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5273805
Commit-Queue: Huiting Yu <huitingyu@google.com>
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1262720}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5311135
Cr-Commit-Position: refs/branch-heads/6312@{#48}
Cr-Branched-From: 6711dcdae48edaf98cbc6964f90fac85b7d9986e-refs/heads/main@{#1262506}

• components/feature_engagement/internal/condition_validator.h[diff]
• components/feature_engagement/internal/feature_config_condition_validator.cc[diff]
• components/feature_engagement/internal/feature_config_condition_validator.h[diff]
• components/feature_engagement/internal/feature_config_condition_validator_unittest.cc[diff]
• components/feature_engagement/internal/never_condition_validator.cc[diff]
• components/feature_engagement/internal/never_condition_validator.h[diff]
• components/feature_engagement/internal/once_condition_validator.cc[diff]
• components/feature_engagement/internal/once_condition_validator.h[diff]
• components/feature_engagement/internal/once_condition_validator_unittest.cc[diff]
• components/feature_engagement/internal/tracker_impl.cc[diff]
• components/feature_engagement/internal/tracker_impl.h[diff]
• components/feature_engagement/internal/tracker_impl_unittest.cc[diff]
• components/feature_engagement/public/BUILD.gn[diff]
• components/feature_engagement/public/default_session_controller.cc[Added - diff]
• components/feature_engagement/public/default_session_controller.h[Added - diff]
• components/feature_engagement/public/session_controller.h[Added - diff]
• components/feature_engagement/public/tracker.h[diff]
• components/feature_engagement/test/test_tracker.cc[diff]