Sync chain should be reset when deleting another device with v2 spec

[darkdh]

Description

Sync chain didn't get reset when there is only one device left on sync chain

Steps to Reproduce

1. Setup sync chain on device a and device b
2. Delete device b from device a
3. Setup new chain on device a and connect device b to it
4. It connect to the previous sync chain. (sync code is still same as step 1)

Actual result:

It connect to the previous sync chain. (sync code is still same as step 1)

Expected result:

Sync chain should be reset when there is only one device on sync chain

Reproduces how often:

Brave version (brave://version info)

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds?

Website problems only:

• Does the issue resolve itself when disabling Brave Shields?
• Is the issue reproducible on the latest version of Chrome?

Additional Information

[GeetaSarvadnya]

Verified the STR mentioned in brave/brave-core#1109. Issue still persists hence reopening the issue.

Step 6 fails, sync code is still same as step3.

Issue is reproducible on

Brave	0.59.12 Chromium: 72.0.3626.17 (Official Build) beta (64-bit)
Revision	08d2140079f8db14c9eb885a803d231b1a30e817-refs/branch-heads/3626@{#315}
OS	Windows 10

Win10 (Bravebeta 0.59.12) to Win10 (BraveDev 0.60.4)

Win10 (Bravebeta 0.59.12) to Linux Mint(Bravebeta 0.59.12)

[GeetaSarvadnya]

Verification passed on

Brave	0.59.18 Chromium: 72.0.3626.28 (Official Build) beta (64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Windows

• Verified the STR from Fix UI initialization flow and reset when devices < 2 from native side brave-core#1109.

Verified passed with:

Brave	0.59.18 Chromium: 72.0.3626.28 (Official Build) beta(64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Mac OS X

• Verified STR from description
• Verified test plan from Reset sync right away if devices size <= 1 brave-core#1191

Verified passed with:

Brave	0.59.18 Chromium: 72.0.3626.28 (Official Build) beta(64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Linux

• Verified the STR from Fix UI initialization flow and reset when devices < 2 from native side brave-core#1109.