CHROMIUM: bluetooth: set advertising intervals after registering advertisements

There are some problems if advertising intervals are set after
registrations of advertisement instances:
- only 1 instance would keep advertising, and
- instead of the original public address, a random address will be used.

The problems are fixed by
- modifying the duration of every existing advertisement instance,
- only modifying the duration if the duration of an instance was
  NOT specified during the registration
  * individual_duration_flag: This adds a flag to mark the
    advertising instances whose advertising durations were provided
    during registration. The advertising durations of the instances
    with this flag set to true would not be modified by the dbus
    SetAdvertisingIntervals method. On the other hand,
    the advertising duration of the instances with this flag
    set to false would be updated with the new values specified
    by the dbus SetAdvertisingIntervals method.
- removing the re-enabling advertising code which is unnecessary.
  Since a new instance will be registered with advertising intervals
  through the regular procedure which makes the configuration of
  advertising simper and robust.

BUG=chromium:655251
TEST=Verify that the two chrome advertising test apps run correctly.

Original App:
Run the original chrome advertising test app which registers
3 advertisement instances *after* setting advertising intervals.
Use nRF Connect, and watch that the advertisement instances are
interleaved in a round-robin manner.

The new App:
Run the chrome advertising test "app2" which registers
3 advertisement instances *before* setting advertising intervals.
Use nRF Connect, and watch that the advertisement instances are
interleaved in a round-robin manner.

Change-Id: I7978e30ad582651124a8decd95808302bdce137c
Reviewed-on: https://chromium-review.googlesource.com/406775
Commit-Ready: Miao-chen Chou <mcchou@chromium.org>
Tested-by: Shyh-In Hwang <josephsih@chromium.org>
Reviewed-by: Rahul Chaturvedi <rkc@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
(cherry picked from commit 2839031c3d631aae1a44c4f56cf8664ed32ad267)
Reviewed-on: https://chromium-review.googlesource.com/412561
Trybot-Ready: Miao-chen Chou <mcchou@chromium.org>
Commit-Queue: Shyh-In Hwang <josephsih@chromium.org>
3 files changed