Add update-desktop-database calls

[rzhao271]

Fixes #193951

[deepak1556]

Changes look good, please verify the following scenarios before merging:

• Install rpm created from this PR on CentOS 7 and verify url handler flow works
• Update the installed package to latest published rpm and verify url handler flow continues to work
• Install deb package from this PR on debian distro and update to latest published version, verify url handler flow works after the update

[rzhao271]

The update scripts currently no-op because the custom Insiders build is newer than the latest published Insiders.
I'll wait until later to test the remaining items.

[rzhao271]

Verified on CentOS 7 the following way:

1. I installed Insiders build 2f2b9e8 which is based off of this branch
2. I ran gio open vscode-insiders://. and verified that code-insiders loaded.
3. I updated code-insiders to 4a0e776 using yum by following the official instructions.
4. I ran gio open vscode-insiders://. and verified that code-insiders loaded.

[rzhao271]

Verified on Ubuntu 22.04 the following way:

1. I installed Insiders build 0f4f31c which is based off of this branch. It's older than the build I used to verify the rpm package, but the most recent change only affects the rpm package post-install scripts, so it's fine.
2. I ran xdg-open vscode-insiders://. and verified that code-insiders loaded.
3. I updated code-insiders to 4a0e776 using apt-get.
4. I ran xdg-open vscode-insiders://. and verified that code-insiders loaded.