JDK 1.7 is supported for all CDH applications as of CDH 4.4 and Cloudera Manager 4.7.
That being said, no version of Cloudera Manager 4.x installs JDK 1.7 during the installation (latest version is 4.8.2). The only version of Cloudera Manager that installs JDK 1.7 automatically is 5.0.0.
To summarize: If you want an automated installation of JDK 1.7 via Cloudera Manager, you need to upgrade to CDH 5, and CM 5.0.0. Alternatively, you could upgrade to CDH4.4, and then perform a manual installation of JDK 1.7.