Reload Brave Private Ads resources after Brave Rewards reset

[aseren]

Need to reload Brave Private Ads resources after Brave Rewards reset only if brave-ads-should-always-run-brave-ads-service flag is enabled.

[btlechowski]

Verification PASSED

Brave	1.58.97 Chromium: 116.0.5845.96 (Official Build) beta (64-bit)
Revision	c983323d5ff7738a3c8d3bf491a7241c24b4d65a
OS	Linux

Verified test plan from brave/brave-core#19522

Run Brave with brave-ads-should-always-run-brave-ads-service

--enable-logging=stderr --vmodule="*/variations/*"=6,"*/bat-native-ledger/*"=6,"*/brave_rewards/*"=6,"*/bat-native-ads/*"=6,"*bat-native-confirmations/*"=6,"*/brave_ads/*"=9,"*/brave_user_model/*"=6,"*/bat_ads/*"=6,"*/whats_new/*"=9 --variations-server-url=https://variations.bravesoftware.com/seed1 --rewards=staging=true,debug=true --use-dev-goupdater-url --enable-features=ShouldAlwaysRunBraveAdsService,ShouldAlwaysTriggerBraveSearchResultAdEvents,ShouldLaunchBraveAdsAsInProcessService,ShouldSupportSearchResultAds,ShouldAlwaysTriggerBraveNewTabPageAdEvents,CustomNotificationAds

Verified conversion resource is loaded:

[14617:14617:0907/194325.905301:VERBOSE1:conversion_resource.cc(54)] Successfully loaded nnqccijfhvzwyrxpxwjrpmynaiazctqb conversion resource
[14617:14617:0907/194325.906382:VERBOSE1:conversion_resource.cc(62)] Successfully initialized nnqccijfhvzwyrxpxwjrpmynaiazctqb conversion resource version 1

opted-in to rewards

Reset rewards

Verified conversion resource is loaded:

[14617:14617:0907/194608.866531:VERBOSE1:conversion_resource.cc(54)] Successfully loaded nnqccijfhvzwyrxpxwjrpmynaiazctqb conversion resource
[14617:14617:0907/194608.866842:VERBOSE1:conversion_resource.cc(62)] Successfully initialized nnqccijfhvzwyrxpxwjrpmynaiazctqb conversion resource version 1