[Android TRM] Add TabResumptionModuleEnablement and tweak isEligible().

The decision logic for whether the Tab Resumption Module shows will be
further complicated by upcoming addition of Local Tab suggestions. This
CL refactors the TRM by extracting the current logic to a new class
TabResumptionModuleEnablement.

The decision logic has multiple layers:
1. Feature enablement: Overarching Chrome setting (e.g., chrome://flags,
   policy). Magic Stack calls ModuleProviderBuilder.isEligible() to get
   this and quickly decide whether the Builder should be instantiated.
2. Other user settings: Runtime-tweakable settings required by the
   module. When Magic Stack calls ModuleProviderBuilder.build() these
   get checked. In general, these can be used to decide whether to
   instantiate suggestion Providers. Also, an already-shown TRM can
   dynamically disappear on settings change. For TRM, these settings
   are:
   * Does the user allows the module to be shown?
   * Is the user signed in?
   * Is sync enabled?
3. Data availability: The TRM only shows if suggestions exist. For
   Foreign Session suggestions, this is not known in build(), and thus
   does not affect Magic Stack decisions and Provider instantiation.
   However, for upcoming Local Tab suggestions, this can be determined
   early on.

In TabResumptionModuleBuilder, previously isEligible() uses both (1) and
(2), and logs failure results there. This is semantically incorrect, so
this CL makes isEligible() to check (1) only (and log on failure), and
move the test for (2) to build() (and log on failure).

For the new class TabResumptionModuleEnablement (and inner classes),
static functions are used to wrap "atomic" conditions and to compose
these to clarify usage semantics. This also makes it easier to compute
@ModuleNotShownReason for logging.

Details:
* Remove TabResumptionModuleMetricsUtils.ModuleVisibility.
  * It is replaced by @ModuleNotShownReason Integer, with null meaning
    module should be shown.
* Add class TabResumptionModuleEnablement:
  * Add inner class ForeignSession:
    * Add isFeatureEnabled() for (1).
    * Add isAllowedByConfig(), isSignedIn(), isSyncEnabled() for (2).
    * Add shouldMakeProvider() as conjunction of (1) and all (2).
  * Add isFeatureEnabled() for (1), replacing
    TabResumptionModuleUtils.shouldShowTabResumptionModule()
  * Add computeModuleNotShownReason() for logging, replacing
    TabResumptionModuleUtils.computeModuleVisibility().
* TabResumptionModuleBuilder: Update usage.

Tests:
* Add TabResumptionModuleEnablementUnitTest(), taking 2 tests from
  TabResumptionModuleUtilsUnitTest(). These tests now also check
  @ModuleNotShownReason values (or null).

Bug: 332588018
Change-Id: Ibe8f3dacc9537f9c3610950c38e949334f9066a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5449681
Reviewed-by: Xi Han <hanxi@chromium.org>
Commit-Queue: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1286720}