Change flag for some attributes

Change flag for some attributes

- Changed attributes
 : MMCAM_CAPTURED_SCREENNAIL, MMCAM_CAPTURED_EXIF_RAW_DATA, MMCAM_DISPLAY_EVAS_SURFACE_SINK
- These attributes are set by mm_attrs_set_* functions internally,
  but, it will return error if flag is not writable
  and there is no way to set them without attribute lock.
  So, change the flag from READABLE to RW.

[Version] 0.10.179
[Profile] Common
[Issue Type] Bug fix
[Dependency module] N/A
[Test] [M(T) - Boot=(OK), sdb=(OK), Home=(OK), Touch=(OK), Version=tizen-unified_20190207.2]

Change-Id: Ia652bd7c371acb794c4d69761fa2f6db2fb7a0a9
Signed-off-by: Jeongmo Yang <jm80.yang@samsung.com>