Automatic merge from submit-queue (batch tested with PRs 52748, 56623). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add brackets around IPv6 addrs in e2e test IP:port endpoints

There are several locations in the e2e tests where endpoints of the
form IPv6:port use IPv6 addresses directly, without surrounding brackets.
Brackets are required around IPv6 addresses in this case, in order to
distinguish the colons in the IPv6 address from the colon immediately
preceding the port.

Also, wherever the curl command might be used with an IPv6 address
surrounded in brackets, the "-g" argument is added to the curl
command line arguments so that the brackets can be interpreted
correctly.

fixes #52746



**What this PR does / why we need it**:
This PR adds brackets around IPv6 addresses when they appear as part of an IPv6-addr:port endpoint
in the e2e tests. This is needed because any connections that attempt to use IPv6-addr:port
endpoint without brackets surrounding the IPv6-addr will fail.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #52746

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```