Importing from Brave (Muon version) when it's open will prompt user to close Brave

[bsclifton]

Description

If a user is doing a manual import from Brave (the older Muon version) and they have Muon open, they'll get an importer locked message (see picture under Actual result)

Test plan / Steps to Reproduce

1. Have an older Brave (release channel) install with profile data
2. Leave the older Brave open
3. Launch Brave Core and use Settings => Import to import from Brave (old)
4. Choose the items and pick Import

Actual result:

Expected result:

Instead of Brave, it should probably say Brave (old) (so that user is not confused and doesn't close the current browser (Brave Core)

Reproduces how often:

100%

Brave version (brave://version info)

0.57.12

[LaurenWags]

Verified passed with

Brave	0.57.16 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Mac OS X

• Verified STR from description
  

Verification Passed on

Brave	0.57.16 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Windows

• Verified the STR from description

Verification Passed on

Brave	0.57.16 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Linux