Revert "Revert "[SettingsProvider] tracking generation of non-pr..."

Revert submission 21910984

Reason for revert: Reland ag/21729397 with changes as follows

* Always fetch a new generation tracker if the generation number changes
* Also merged ag/21876270 (minor improvement) with this CL

Reverted changes: /q/submissionid:21910984

BUG: 228619157
Test: atest android.provider.NameValueCacheTest
Test: atest CtsNetTestCasesLatestSdk:android.net.cts.ConnectivityManagerTest#testUidsAllowedOnRestrictedNetworks
Test: atest android.widget.TextViewPrecomputedTextPerfTest#testOnMeasure_RandomText
Change-Id: Ib0c8c4e25dfa5cb0b01559e60bd95d2ea668decc