Populate process.command_args for Java 9+ and improve process.command_line for Java 8

[tylerbenson]

command_args is defined as:

All the command arguments (including the command/executable itself) as received by the process. On Linux-based systems (and some other Unixoid systems supporting procfs), can be set according to the list of null-delimited strings extracted from proc/[pid]/cmdline. For libc-based executables, this would be the full argv vector passed to main.

process.command_line only included vm arguments, not the program arguments:

The full command used to launch the process as a single string representing the full command. On Windows, can be set to the result of GetCommandLineW. Do not set this if you have to assemble it just for monitoring; use process.command_args instead.

Based on review below, I opted to only provide command_line for Java 8 and prefer command_args for Java 9+.

[tylerbenson]

When running the test in intellij, it generates an attribute like this:

attributes.get(ResourceAttributes.PROCESS_COMMAND_ARGS) = {ArrayList@2627}  size = 11
 0 = ".../Library/Java/JavaVirtualMachines/java/Contents/Home/bin/java"
 1 = "-agentlib:jdwp=transport=dt_socket,address=127.0.0.1:64303,suspend=y,server=n"
 2 = "-ea"
 3 = "-Didea.test.cyclic.buffer.size=1048576"
 4 = "-javaagent:.../Library/Caches/JetBrains/IntelliJIdea/groovyHotSwap/gragent.jar"
 5 = "-javaagent:.../Library/Caches/JetBrains/IntelliJIdea/captureAgent/debugger-agent.jar=file:/private/var/folders/vj/.../T/capture1.props"
 6 = "-Dfile.encoding=UTF-8"
 7 = "com.intellij.rt.junit.JUnitStarter"
 8 = "-ideVersion5"
 9 = "-junit5"
 10 = "io.opentelemetry.instrumentation.resources.ProcessResourceTest"