No obvious way to set JDT settings

I would like to use the "Text Blocks" feature of Java 13. I have the Java 13 JDK installed and that is being picked up correctly by VSCode.

In addition, I have modified my "pom.xml" file to include the "--enable-preview" JVM argument that turns on this feature, like so:

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
				<configuration>
					<jvmArguments>--enable-preview</jvmArguments>
				</configuration>
			</plugin>
		</plugins>
	</build>

I also attempted to edit the .settings/org.eclipse.jdt.core.prefs file and set org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=enabled but any changes to this file are overwritten when the "Clean the java language workspace" task is run

Environment

• Operating System: Linux
• JDK version: 13
• Visual Studio Code version: 1.40.1
• Java extension version: 0.53.1

Steps To Reproduce

1. Create Java project with Java 13
2. Attempt to use Text Block syntax

Current Result

Expected Result

I expect to be able to enable preview features in JDT and for Text Blocks to work with no compiler error

Reproduce the Java 13 Text Blocks error in a project using the shown pom.xml configuration, then inspect how the .settings/org.eclipse.jdt.core.prefs file is generated when the Java language workspace is cleaned. Done means preview features remain enabled in JDT and Text Block syntax produces no compiler error.