SdkSandboxShellCommand: Allow ROOT_UID and SHELL_UID

Allows process with ROOT_UID or SHELL_UID to run the shell command for
sdk_sandbox. Updates SdkSandboxShellHostTest to enable adb root.

Bug: 227981627
Test: atest SdkSandboxShellHostTest
Change-Id: Ibb96a0b949903dd6db1bd08d7581f5fe7dd47dc6
2 files changed