Allow writing to externally provided JDK

[wendigo]

Some product test environments can import certificates to cacerts, which will fail if the externally provided JDK is mounted read-only.

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Additional context and related issues

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# Section
* Fix some things. ({issue}`issuenumber`)

[wendigo]

I've verified locally that the custom JDK is mounted read-writeable:

        "Mounts": [
            {
                "Type": "bind",
                "Source": "/Users/mateuszgajewski/Projects/src/github.com/trinodb/trino/core/trino-server/target/trino-server-425-SNAPSHOT.tar.gz",
                "Destination": "/docker/presto-server.tar.gz",
                "Mode": "ro",
                "RW": false,
                "Propagation": "rprivate"
            },
            {
                "Type": "bind",
                "Source": "/var/folders/n4/vl45d5rn5n1_yk_pl5xkpd380000gn/T/ptl-tmp-download/zulu21-ea-arm64/zulu21.0.57-ea-jdk21.0.0-ea.22-linux_aarch64",
                "Destination": "/usr/lib/jvm/zulu21-ea",
                "Mode": "rw",
                "RW": true,
                "Propagation": "rprivate"
            }
        ],