Updating from an older version fails to enable ads

[srirambv]

Description

Updating from an older version fails to enable ads

Steps to Reproduce

1. Install an older build say (0.58.21)
2. Enable Rewards. ensure ads is not available
3. Upgrade to 0.63.48
4. Ads shows sorry not available for your region even if the criteria matches

Actual result:

Updating from an older version fails to enable ads

Expected result:

Should enable ads post upgrade

Reproduces how often:

Easy

Miscellaneous Information:

Issue reproduced on all platforms.
cc: @tmancey @ryanml @jsecretan

[LaurenWags]

Encountered #4404 while testing

[LaurenWags]

Verified passed with

Brave	0.64.74 Chromium: 74.0.3729.131 (Official Build) (64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Mac OS X

• Verified test plan from Fixes Ads region supported message on upgrade paths from 0.58.x brave-core#2340
• Verified if you update from 0.58.21 to 0.63.55, you encounter the issue as described, but when you update to 0.64.74 on test channel the issue no longer reproduces, you will encounter scenario 1 as described in Updating from older build doesn't show notification to try Ads #4404
• Updating from 0.58.21 and 0.59.35 to 0.64.74 directly (skipping 0.63.x versions) no longer reproduces the issue but does encounter scenario 2 from Updating from older build doesn't show notification to try Ads #4404
• Updating from 0.60.45, 0.61.51, 0.62.51 directly (skipping 0.63.x versions) no longer reproduces the issue, also Updating from older build doesn't show notification to try Ads #4404 is not encountered

Verification passed on

Brave	0.64.75 Chromium: 74.0.3729.131 (Official Build) (64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Linux

• Encountered Updating from older build doesn't show notification to try Ads #4404 while updating from 0.58.x to 0.64.x directly

Verification passed on

Brave	0.64.75 Chromium: 74.0.3729.131 (Official Build) (64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Windows 10 OS Build 17134.523

• Encountered Updating from older build doesn't show notification to try Ads #4404 while testing