fix: improved conditions for plane symbol on plan page

[Saschl]

Fixes plane symbol on plan mode showing incorrectly before ppos is available.

Fixes #[issue_no]

Summary of Changes

Screenshots (if necessary)

References

Additional context

Discord username (if different from GitHub):

Testing instructions

1. Start C&D, power up plane and select PLAN mode on ND
2. Set all three ADIRS to NAV and wait for alignment.
3. Plane symbol should not appear before alignment is completely finished.
4. Check that the orientation and position of the symbol is correct.
5. Verify the symbol moves and rotates correctly when taxiing and after takeoff.

How to download the PR for QA

Every new commit to this PR will cause new A32NX and A380X artifacts to be created, built, and uploaded.

1. Make sure you are signed in to GitHub
2. Click on the Checks tab on the PR
3. On the left side, find and click on the PR Build tab
4. Click on either flybywire-aircraft-a320-neo or flybywire-aircraft-a380-842 download link at the bottom of the page

[LunakisDev]

Quality Assurance Trainee Report

Discord: LunakisLeaks
Object of testing: #8653
Tier of Testing : 1
Date: 16/5/2024

Testing Process:

1. Spawned at LGAV in C&D state
2. Started the aircraft
3. Align of the ADIRS
4. Set up FPLN PERF etc
5. taxied around in the airport to verify the symbol moves and rotates correctly when taxiing
6. Full flight to test the symbol in the air

Negatives:
N/A

Testing Results:
Passed

Conclusions:
LGTM