hw encoder: set_bitrate and apply_bitrate based on Param (#38095)

* initial codex

* remove ISP delay from encode ms

* try something simpler

* not allowing increase bug

* decrease bitrate increase rate

* upsample only on consecutive good checks

* rearrange

* clean

* Revert frame timing processing time change

* clean

* remove bitrate option and just do it on --stream

* make set_bitrate a lot more simple

* clean default impl

* further cleaning

* struct for bitrate to pass ci

* refactor a bit

* add comment

* small clean

* add init()

* increase bitrate

* update ffmpeg message

* remove unnecessary include

* modify set_bitrate

* change to Param

* remove getInt helper; add back in diff pr

* reword unclear error message

* move webrtcd change to new branch

common/params_keys.h

@@ -80,6 +80,7 @@ inline static std::unordered_map<std::string, ParamKeyAttributes> keys = {
     {"LiveDelay", {PERSISTENT, BYTES}},
     {"LiveParameters", {PERSISTENT, JSON}},
     {"LiveParametersV2", {PERSISTENT, BYTES}},
+    {"LivestreamEncoderBitrate", {CLEAR_ON_MANAGER_START | DONT_LOG, INT}},
     {"LiveTorqueParameters", {PERSISTENT | DONT_LOG, BYTES}},
     {"LocationFilterInitialState", {PERSISTENT, BYTES}},
     {"LateralManeuverMode", {CLEAR_ON_MANAGER_START | CLEAR_ON_OFFROAD_TRANSITION, BOOL}},