unity-builder: Private Repositories bug

Bug description

I am trying to build my Unity Project to Android using the GameCI. My project uses private repositories with ssh. I follow the documentation and I put the SSH Agent step in my CI. I add the Deploy Key to my repository and add the secret key to Secrets.

But this error occurs:

com.company.utils: Error when executing git command. Failed to add the RSA host key for IP address '140.82.112.3' to the list of known hosts (/root/.ssh/known_hosts).
    ERROR: Repository not found.
    fatal: Could not read from remote repository.

I already try to add the ips in /home/runner/.ssh/known_hosts. The command below does not return errors:

Run ssh-keyscan 140.82.114.3 >> /home/runner/.ssh/known_hosts
  ssh-keyscan 140.82.114.3 >> /home/runner/.ssh/known_hosts
  shell: /usr/bin/bash -e {0}
  env:
    SSH_AUTH_SOCK: /tmp/ssh-BYQRT89SNPb3/agent.1664
    SSH_AGENT_PID: 1665
# 140.82.114.3:22 SSH-2.0-babeld-968490c5
# 140.82.114.3:22 SSH-2.0-babeld-968490c5
# 140.82.114.3:22 SSH-2.0-babeld-968490c5
# 140.82.114.3:22 SSH-2.0-babeld-968490c5
# 140.82.114.3:22 SSH-2.0-babeld-968490c5

When I try to add to /root/.ssh/known_hosts, the error occurs:

Run ssh-keyscan github.com >> /root/.ssh/known_hosts
  ssh-keyscan github.com >> /root/.ssh/known_hosts
  shell: /usr/bin/bash -e {0}
  env:
    SSH_AUTH_SOCK: /tmp/ssh-3ZIaGpOiiIJn/agent.1641
    SSH_AGENT_PID: 1642
/home/runner/work/_temp/8d9c2b71-d5e1-4648-b27e-5f695d8e3558.sh: line 1: /root/.ssh/known_hosts: Permission denied
Error: Process completed with exit code 1.

How to reproduce

• Create a unity project that uses private repositories with ssh

• Try to run CI Unity Build

Expected behavior

Build the project with success

CI File

name: Actions 😎

on: [push, pull_request]

jobs:
  build:
    name: Build Project ✨ for ${{ matrix.targetPlatform }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        projectPath:
          - xproject-unity
        unityVersion: 
          - 2020.3.11f1
        targetPlatform:
          - Android
    steps:
      # Checkout
      - name: Checkout repository
        uses: actions/checkout@v2
        with:
          fetch-depth: 0

      - name: SSH Agent
        uses: webfactory/ssh-agent@v0.5.3
        with:
          ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}

      - name: Adding github to known_hosts
        run: ssh-keyscan github.com >> /root/.ssh/known_hosts

      - name: Adding github to known_hosts
        run: ssh-keyscan 140.82.114.3 >> /root/.ssh/known_hosts

      - name: Adding github to known_hosts
        run: ssh-keyscan 140.82.114.4 >> /root/.ssh/known_hosts

      # Cache
      - uses: actions/cache@v2
        with:
          path: ${{ matrix.projectPath }}/Library
          key: Library-${{ matrix.targetPlatform }}
          restore-keys: |
            Library-${{ matrix.targetPlatform }}-
            Library-

      # Build
      - name: Build project
        uses: game-ci/unity-builder@v2
        env:
          UNITY_LICENSE: ${{ secrets.UNITY_LICENSE }}
        with:
          sshAgent: ${{ env.SSH_AUTH_SOCK }}
          projectPath: ${{ matrix.projectPath }}
          unityVersion: ${{ matrix.unityVersion }}
          targetPlatform: ${{ matrix.targetPlatform }}
          versioning: Semantic
          androidAppBundle: false
          androidKeystoreName: x.keystore
          androidKeystoreBase64: ${{ secrets.ANDROID_KEYSTORE_BASE64 }}
          androidKeystorePass: ${{ secrets.ANDROID_KEYSTORE_PASS }}
          androidKeyaliasName: ${{ secrets.ANDROID_KEYALIAS_NAME }}
          androidKeyaliasPass: ${{ secrets.ANDROID_KEYALIAS_PASS }}

      # Output
      - uses: actions/upload-artifact@v2
        with:
          name: Build-${{ matrix.targetPlatform }}
          path: build/${{ matrix.targetPlatform }}