submit/tizen_5.5/20200120.080455

Applying streamrecorder mode APIs to internal.

It is branch merging of tizen 6.0.
(https://review.tizen.org/gerrit/#/c/platform/core/api/mediastreamrecorder/+/218535/)

[Modification]
- Generates internal header, c file.
- 'streamrecoder_set_mode' and 'streamrecorder_get_mode' goes to internal.
- 'streamrecorder_mode_e' enum goes to internal.
- Adds testsuite for loopback test.