Extend a set of options in WriteOption to allow defining the log location as custom project, folder, org or billing account

[minherz]

Currently, the set of WriteOption options is limited to

java-logging/google-cloud-logging/src/main/java/com/google/cloud/logging/Logging.java

Lines 69 to 72 in 9d0e7a2

	enum OptionType implements Option.OptionType {
	LOG_NAME,
	RESOURCE,
	LABELS;

and does not allow to customize log name. The location of the log is produced based on the project id which is taken from the logging client options:

java-logging/google-cloud-logging/src/main/java/com/google/cloud/logging/LoggingImpl.java

Lines 741 to 746 in 9d0e7a2

	String projectId = serviceOptions.getProjectId();
	WriteLogEntriesRequest.Builder builder = WriteLogEntriesRequest.newBuilder();
	String logName = LOG_NAME.get(options);
	if (logName != null) {
	builder.setLogName(LogName.ofProjectLogName(projectId, logName).toString());
	}

This project id is retrieved from authentication workflow and is not necessary the same with the needed log destination. There also cases when the destination should be other than a project

[minherz]

The implementation should be similar to TailOption. However, there should be a constraint to provide only one option among project, folder, org and billing_acc ids.
Also it worth to add tests that will validate the log name constraints:

• [LOG_NAME] must be URL-encoded
• [LOG_NAME] must be less than 512 characters long and can only include the following characters: upper and lower case alphanumeric characters, forward-slash, underscore, hyphen, and period.
• [LOG_NAME] must NOT start with forward-slash
• [PROJECT] must be less than or equal than 30 characters long and can only include the following characters: lowercase letters, numbers, and hyphens.
• [PROJECT] must start with a letter, cannot end with a hyphen and cannot contain restricted strings, such as google and ssl.
• [FOLDER] and [ORGANIZATION] can only include numeric characters.
• [BILLINGACCOUNT] must follow XXXXXX-XXXXXX-XXXXXX pattern where X can be lower case alphanumeric characters.

It can be a good idea to extend the above validation to other *Option values.