az command not executable

## Describe the bug

**Command Name**
`az login`

**Errors:**
`-bash: /home/ubuntu/aztest/bin/az: Permission denied`

## To Reproduce:
```
python3 -m virtualenv aztest
source aztest/bin/activate
pip install azure-cli
az login
```
## Expected Behavior
az should be installed with the executable bit set:

```
ll /home/ubuntu/csitest/bin/az
-rw-r----- 1 ubuntu ubuntu 482 Mar 25 11:15 /home/ubuntu/functionvenv/bin/az
```

setting the bit fixes it
```
chmod +x /home/ubuntu/functionvenv/bin/az
az login
```
## Environment Summary
```
Linux-5.4.0-1043-azure-x86_64-with-glibc2.29
Python 3.8.5
Installer: PIP

azure-cli 2.21.0

```
## Additional Context