McLaren boss Andrea Stella is confident rookie driver Oscar Piastri can stay within the "bubble" during his first Formula 1 Australian Grand Prix. Piastri, who was born in Melbourne, is set for his first home Grand Prix in just his third start next weekend amid a poor start to the season for McLaren. The team announced the departure of Technical Director James Key earlier in the week in a reshuffle and restructure, with the impact of the much-talked about Azerbaijan upgrade package also being played down by Stella. Despite the car troubles and the expected noise around Piastri at his…