Perform null check when calling Start on DriverService

[jordan-mace]

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Description

Implements the null-check found in the Java bindings. For further details on the problem at hand, check out the description and comment thread of #8074

Motivation and Context

Fixes #8074

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.