AKVVM: /lib64/libstdc++.so.6: version `CXXABI_1.3.9' not found

Running the `Microsoft.Azure.KeyVault` VM extension (`akvvm_service`) on CentOS 7.8 results in the following errors:
```
Jun 08 10:15:39 test.example.com akvvm_service[1314]: /var/lib/waagent/Microsoft.Azure.KeyVault.KeyVaultForLinux-1.0.1172.13/akvvm_service: /lib64/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /var/lib/waagent/Microsoft.Azure.KeyVault.KeyVaultForLinux-1.0.1172.13/akvvm_service)
Jun 08 10:15:39 test.example.com akvvm_service[1314]: /var/lib/waagent/Microsoft.Azure.KeyVault.KeyVaultForLinux-1.0.1172.13/akvvm_service: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /var/lib/waagent/Microsoft.Azure.KeyVault.KeyVaultForLinux-1.0.1172.13/akvvm_service)
Jun 08 10:15:39 test.example.com akvvm_service[1314]: /var/lib/waagent/Microsoft.Azure.KeyVault.KeyVaultForLinux-1.0.1172.13/akvvm_service: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /var/lib/waagent/Microsoft.Azure.KeyVault.KeyVaultForLinux-1.0.1172.13/akvvm_service)
```

The given version of `libstdc++.so` on CentOS 7.8 only contains the following version:
```sh
[root@test ~]# strings /lib64/libstdc++.so.6.0.19 | egrep "GLIBCXX_|CXXABI_"
GLIBCXX_3.4
GLIBCXX_3.4.1
GLIBCXX_3.4.2
GLIBCXX_3.4.3
GLIBCXX_3.4.4
GLIBCXX_3.4.5
GLIBCXX_3.4.6
GLIBCXX_3.4.7
GLIBCXX_3.4.8
GLIBCXX_3.4.9
GLIBCXX_3.4.10
GLIBCXX_3.4.11
GLIBCXX_3.4.12
GLIBCXX_3.4.13
GLIBCXX_3.4.14
GLIBCXX_3.4.15
GLIBCXX_3.4.16
GLIBCXX_3.4.17
GLIBCXX_3.4.18
GLIBCXX_3.4.19
CXXABI_1.3
CXXABI_1.3.1
CXXABI_1.3.2
CXXABI_1.3.3
CXXABI_1.3.4
CXXABI_1.3.5
CXXABI_1.3.6
CXXABI_1.3.7
CXXABI_TM_1
GLIBCXX_DEBUG_MESSAGE_LENGTH
```

Is there a specific version of the `Microsoft.Azure.KeyVault` extension which can be used on CentOS 7?

Start by reviewing the Microsoft.Azure.KeyVault VM extension and its akvvm_service entry point on CentOS 7.8, then compare the extension's required CXXABI and GLIBCXX versions with /lib64/libstdc++.so.6. Done means identifying a compatible extension version or documenting that no supported version works on this platform.

Written by the indexing model from the issue text.