Emulator 29.0.4 Canary

Emulator 29.0.4 is now available in the Canary and Dev channels. Changes:

• Added back the -gpu angle_indirect rendering option for Windows.
• Linux: We have found that on certain host kernels, the guest Android kernel can error out and exit in KVM with a "hardware error." We now abort() the emulator when this happens in order to increase debuggability (previously, it just hung).
• Linux: For convenience with CI setups, added command line option -stdouterr-file <file-name> to redirect both stdout and stderr to a file.
• To improve reliability of multiple emulator instances, if launching multiple instances of the emulator with -read-only, sometimes the previous writable emulator instance is not yet done cleaning up stale files. The emulator now retries to launch multiple instances 3 times over 3 seconds in that case.
• Fixed parsing of -allow-host-audio command line option.