Fix #1027: properly detect new mysql connector

[anthonydahanne]

• Mysql connector was renamed recently from mysql-connector-java to mysql-connector-j, and needs to be detected by the buildpack
• Rephrase documentation to make it more obvious that if a maria db client or mysql connector exist, the buildpack should not add its own mariadb connector

[anthonydahanne]

@pivotal-david-osullivan : tested with spring-music:

cf push -b java_buildpack_offline
[...]
Staging app and tracing logs...
   Downloading java_buildpack_offline...
   Downloaded java_buildpack_offline
   Cell e298fb9e-bbf1-4fab-82f4-73173334b79e creating container for instance cf7f4cc8-539c-47b0-8fde-d95a231a55fc
   Security group rules were updated
   Cell e298fb9e-bbf1-4fab-82f4-73173334b79e successfully created container for instance cf7f4cc8-539c-47b0-8fde-d95a231a55fc
   Downloading build artifacts cache...
   Downloading app package...
   Downloaded build artifacts cache (132B)
   Downloaded app package (59.2M)
   -----> Java Buildpack v4.60.0 (offline) | https://github.com/cloudfoundry/java-buildpack#9f8aba60
   -----> Downloading Jvmkill Agent 1.17.0_RELEASE from https://java-buildpack.cloudfoundry.org/jvmkill/jammy/x86_64/jvmkill-1.17.0-RELEASE.so (found in cache)
   -----> Downloading Open Jdk JRE 17.0.7_7 from https://java-buildpack.cloudfoundry.org/openjdk/jammy/x86_64/bellsoft-jre17.0.7%2B7-linux-amd64.tar.gz (found in cache)
   Expanding Open Jdk JRE to .java-buildpack/open_jdk_jre (4.0s)
   JVM DNS caching disabled in lieu of BOSH DNS caching
   -----> Downloading Open JDK Like Memory Calculator 3.13.0_RELEASE from https://java-buildpack.cloudfoundry.org/memory-calculator/jammy/x86_64/memory-calculator-3.13.0-RELEASE.tar.gz (found in cache)
   Loaded Classes: 28526, Threads: 250
   -----> Downloading Client Certificate Mapper 1.11.0_RELEASE from https://java-buildpack.cloudfoundry.org/client-certificate-mapper/client-certificate-mapper-1.11.0-RELEASE.jar (found in cache)
   -----> Downloading Container Security Provider 1.20.0_RELEASE from https://java-buildpack.cloudfoundry.org/container-security-provider/container-security-provider-1.20.0-RELEASE.jar (found in cache)
   -----> Downloading Maria Db JDBC 2.7.9 from https://java-buildpack.cloudfoundry.org/mariadb-jdbc/mariadb-jdbc-2.7.9.jar (found in cache)

and then with:

 cf push -b https://github.com/anthonydahanne/java-buildpack.git\#fix-1027-mysql-name
[...]
Staging app and tracing logs...
   Cell 8cc5b721-601c-491e-b02f-39956e5cd18b creating container for instance a948622c-c196-4571-827f-9681f6b27907
   Security group rules were updated
   Cell 8cc5b721-601c-491e-b02f-39956e5cd18b successfully created container for instance a948622c-c196-4571-827f-9681f6b27907
   Downloading app package...
   Downloading build artifacts cache...
   Downloaded build artifacts cache (132B)
   Downloaded app package (59.2M)
   -----> Java Buildpack 2445d65 | https://github.com/anthonydahanne/java-buildpack.git#2445d65
   -----> Downloading Jvmkill Agent 1.17.0_RELEASE from https://java-buildpack.cloudfoundry.org/jvmkill/jammy/x86_64/jvmkill-1.17.0-RELEASE.so (0.1s)
   -----> Downloading Open Jdk JRE 17.0.8_7 from https://java-buildpack.cloudfoundry.org/openjdk/jammy/x86_64/bellsoft-jre17.0.8%2B7-linux-amd64.tar.gz (0.7s)
   Expanding Open Jdk JRE to .java-buildpack/open_jdk_jre (1.7s)
   JVM DNS caching disabled in lieu of BOSH DNS caching
   -----> Downloading Open JDK Like Memory Calculator 3.13.0_RELEASE from https://java-buildpack.cloudfoundry.org/memory-calculator/jammy/x86_64/memory-calculator-3.13.0-RELEASE.tar.gz (0.1s)
   Loaded Classes: 28526, Threads: 250
   -----> Downloading Client Certificate Mapper 1.11.0_RELEASE from https://java-buildpack.cloudfoundry.org/client-certificate-mapper/client-certificate-mapper-1.11.0-RELEASE.jar (0.0s)
   -----> Downloading Container Security Provider 1.20.0_RELEASE from https://java-buildpack.cloudfoundry.org/container-security-provider/container-security-provider-1.20.0-RELEASE.jar (0.3s)

In both cases, the app was running fine, except in the first case the injected MariaDB connector was injected