7883 ClassCastException when using -Dotel.jmx.target.system=tomcat (#7884)

Using "1" to specify units of plain cardinality.

instrumentation/jmx-metrics/javaagent/src/main/resources/jmx/rules/hadoop.yaml

@@ -1,7 +1,7 @@
 ---
 rules:
  - bean: Hadoop:service=NameNode,name=FSNamesystem
-   unit: 1
+   unit: "1"
    prefix: hadoop.
    metricAttribute:
      node_name: param(tag.Hostname)

instrumentation/jmx-metrics/javaagent/src/main/resources/jmx/rules/jetty.yaml

@@ -44,7 +44,7 @@ rules:
     mapping:
       selectCount:
         type: counter
-        unit: 1
+        unit: "1"
         desc: The number of select calls
 
   - bean: org.eclipse.jetty.logging:type=jettyloggerfactory,id=*
@@ -52,5 +52,5 @@ rules:
     mapping:
       LoggerCount:
         type: updowncounter
-        unit: 1
+        unit: "1"
         desc: The number of registered loggers by name

instrumentation/jmx-metrics/javaagent/src/main/resources/jmx/rules/tomcat.yaml

@@ -1,7 +1,7 @@
 ---
 rules:
  - bean: Catalina:type=GlobalRequestProcessor,name=*
-   unit: 1
+   unit: "1"
    prefix: http.server.tomcat.
    metricAttribute:
      name: param(name)
@@ -39,7 +39,7 @@ rules:
        metricAttribute:
          direction: const(sent)
  - bean: Catalina:type=Manager,host=localhost,context=*
-   unit: 1
+   unit: "1"
    prefix: http.server.tomcat.
    type: updowncounter
    metricAttribute:

instrumentation/jmx-metrics/javaagent/src/main/resources/jmx/rules/wildfly.yaml

@@ -5,7 +5,7 @@ rules:
      deployment: param(deployment)
    prefix: wildfly.session.
    type: counter
-   unit: 1
+   unit: "1"
    mapping:
      sessionsCreated:
      activeSessions:
@@ -18,7 +18,7 @@ rules:
      listener: param(http-listener)
    prefix: wildfly.request.
    type: counter
-   unit: 1
+   unit: "1"
    mapping:
      requestCount:
      processingTime:
@@ -42,7 +42,7 @@ rules:
        metricAttribute:
          direction: const(in)
  - bean: jboss.as:subsystem=datasources,data-source=*,statistics=pool
-   unit: 1
+   unit: "1"
    metricAttribute:
      data_source: param(data-source)
    mapping: