Java: Properly resolve issues in java/spotbugs-exclude.xml #1113

Describe the bug
The bug patterns being excluded in java/spotbugs-exlude.xml should be addressed in the code.

To Reproduce
Steps to reproduce the behavior:

1. checkout the experimental-java branch
2. cd java
3. ./mvnw clean verify -Pbug-check

Expected behavior
There should not be a spotbugs-exclude.xml. We should not get any spotbugs errors when compiling with -Pbug-check.
NOTE: This isn't entirely true. There may be issues that we just cannot resolve, or we may know better than spotbugs.

Screenshots
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Desktop (please complete the following information):

• OS: [e.g. Windows]
• IDE: [e.g. Visual Studio, VS Code]
• NuGet Package Version [e.g. 0.1.0]

Additional context
Add any other context about the problem here.