docs(boxsdkgen): Add migration guides for Java (box/box-codegen#867)

[box-sdk-build]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build #5319

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 15 unchanged lines in 9 files lost coverage.
• Overall coverage increased (+0.009%) to 13.665%

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Files with Coverage Reduction	New Missed Lines	%
src/main/java/com/box/sdk/BoxFileUploadSession.java	1	64.67%
src/main/java/com/box/sdk/EventStream.java	1	86.46%
src/main/java/com/box/sdkgen/client/BoxClient.java	1	0.0%
src/main/java/com/box/sdkgen/networking/defaultnetworkclient/DefaultNetworkClient.java	1	0.0%
src/main/java/com/box/sdk/MetadataQuery.java	1	92.41%
src/main/java/com/box/sdkgen/box/ccgauth/BoxCCGAuth.java	2	0.0%
src/main/java/com/box/sdkgen/box/jwtauth/JWTConfig.java	2	0.0%
src/main/java/com/box/sdk/MetadataTemplate.java	2	68.27%
src/main/java/com/box/sdkgen/box/eventstream/EventStreamIterator.java	4	0.0%

Totals
Change from base Build #5301:	0.009%
Covered Lines:	8374
Relevant Lines:	61282

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💛 - Coveralls