Can't dismiss grant notification

[emerick]

Description

It's possible to get into a state where a user is unable to dismiss a grant notification. This is most likely due to an old installation leaving an invalid value in Preferences.

Steps to Reproduce

1. Delete your existing profile
2. Launch Brave
3. Opt-in to Rewards
4. Close Brave without dismissing the grant notification
5. In your profile directory, open the Preferences file and in the brave.rewards.notifications section set id to 0
6. Save the Preferences file
7. Launch Brave
8. Try to dismiss grant notification by clicking its OK button

Actual result:

Grant notification can't be dismissed

Expected result:

Grant notification is dismissed when you click OK

Reproduces how often:

Always

[GeetaSarvadnya]

Verification passed on

Brave	0.56.9 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Windows

Verification passed on

Brave	0.56.10 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Linux

• Verified notifications stacked on 0.55.22 gets dismissed when upgraded to 0.56.10

Verified passed with

Brave	0.56.10 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Mac OS X

• Verified notifications stacked on 0.55.22 gets dismissed when upgraded to 0.56.10
• Verified STR from description

Went through verification using the following build under macOS 10.14 x64 - PASSED

Brave	0.56.10 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Mac OS X

• stacked 20 notifications using 0.55.20, updated to 0.56.10 and ensured that you could dismiss the notifications
• stacked 20 notifications using 0.55.22, updated to 0.56.10 and ensured that you could dismiss the notifications
• ensured that you can dismiss "brave":{"rewards":{"notifications":"[{\"args\":[],\"id\":\"0\",\"timestamp\":1541706932,\"type\":2}
• ensured that you can dismiss "brave":{"rewards":{"notifications":"[{\"args\":[],\"id\":0,\"timestamp\":1541707248,\"type\":2}]"}