[Android] Fix crash in GraphicsView when using TapGestureRecognizer

[jpd21122012]

Description of Change

Fixes a crash on Android when using TapGestureRecognizer with GraphicsView.

Root Cause

PlatformTouchGraphicsView.TouchesMoved assumed that _lastMovedViewPoints
always contained at least one element.

In certain touch event sequences (triggered when a TapGestureRecognizer is attached),
_lastMovedViewPoints could be empty while points.Length == 1,
leading to an IndexOutOfRangeException.

Fix

Added a length check before accessing _lastMovedViewPoints[0]
to prevent out-of-range access.

Verified Scenarios

• TapGestureRecognizer no longer causes a crash
• Tap events fire correctly
• Drag interaction remains functional
• Multitouch does not crash

Fixes #34296

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 34301

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 34301"

[dotnet-policy-service]

Hey there @@jpd21122012! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[PureWeen]

/azp run maui-pr-uitests, maui-pr-devicetests

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[PureWeen]

/azp run maui-pr-uitests, maui-pr-devicetests

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).