add update to apt-get for sqlite CI machine install

[IanMatthewHuff]

For #8883

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Has a news entry file (remember to thank yourself!)
• Appropriate comments and documentation strings in the code
• Has sufficient logging.
• Has telemetry for enhancements.
• Unit tests & system/integration tests are added/updated
• Test plan is updated as appropriate
• package-lock.json has been regenerated by running npm install (if dependencies have changed)
• The wiki is updated with any design decisions/details.

[codecov-io]

Codecov Report

Merging #8924 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #8924   +/-   ##
=======================================
  Coverage   58.16%   58.16%           
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  Files         529      529           
  Lines       27634    27634           
  Branches     4162     4162           
=======================================
  Hits        16073    16073           
  Misses      10671    10671           
  Partials      890      890

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[IanMatthewHuff]

Context. On CI Linux machines our "Setup python to run with sqlite on 3.*" step has started failing recently. The first part of that step is to run the following:
sudo apt-get install libsqlite3-dev

A week or so ago on a working build:

The following NEW packages will be installed:
  libsqlite3-dev
0 upgraded, 1 newly installed, 0 to remove and 22 not upgraded.
Need to get 509 kB of archives.
After this operation, 1,708 kB of additional disk space will be used.
Get:1 http://azure.archive.ubuntu.com/ubuntu xenial-updates/main amd64 libsqlite3-dev amd64 3.11.0-1ubuntu1.2 [509 kB]

Last night the same step on a failing build:

The following NEW packages will be installed:
  libsqlite3-dev
0 upgraded, 1 newly installed, 0 to remove and 22 not upgraded.
Need to get 509 kB of archives.
After this operation, 1,708 kB of additional disk space will be used.
Err:1 http://security.ubuntu.com/ubuntu xenial-security/main amd64 libsqlite3-dev amd64 3.11.0-1ubuntu1.2
  404  Not Found
Err:1 http://security.ubuntu.com/ubuntu xenial-security/main amd64 libsqlite3-dev amd64 3.11.0-1ubuntu1.2
  404  Not Found
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/s/sqlite3/libsqlite3-dev_3.11.0-1ubuntu1.2_amd64.deb  404  Not Found

E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

Noting the comment on the end of the failure (and seeing that many azure apt-get steps listed online start out with an apt-get update. I've added an apt-get update before the install line.

[IanMatthewHuff]

Smoke Linux passes on my test build:
https://dev.azure.com/ms/vscode-python/_build/results?buildId=52963

The Install step now looks like this:

[command]/bin/bash --noprofile --norc /home/vsts/work/_temp/c012c483-8ee1-4d24-b980-d12282d95586.sh
Hit:1 http://azure.archive.ubuntu.com/ubuntu xenial InRelease
Get:2 http://azure.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
<IANHU SNIP LIST>
Get:53 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial/main amd64 Packages [87.6 kB]
Get:54 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial/main Translation-en [14.6 kB]
Fetched 5,354 kB in 10s (535 kB/s)
Reading package lists...
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  libsqlite3-0
Suggested packages:
  sqlite3-doc
The following NEW packages will be installed:
  libsqlite3-dev
The following packages will be upgraded:
  libsqlite3-0
1 upgraded, 1 newly installed, 0 to remove and 317 not upgraded.
Need to get 906 kB of archives.
After this operation, 1,708 kB of additional disk space will be used.
Get:1 http://azure.archive.ubuntu.com/ubuntu xenial-updates/main amd64 libsqlite3-0 amd64 3.11.0-1ubuntu1.3 [397 kB]
Get:2 http://azure.archive.ubuntu.com/ubuntu xenial-updates/main amd64 libsqlite3-dev amd64 3.11.0-1ubuntu1.3 [509 kB]