[roll] Roll fuchsia [antigravity-agent-generated] [profiler] Fix stack capture for AArch32 threads

Fixes DWARF stack sampling:
1. Uses live R13 (x[13]) as the capture address for AArch32 threads. Previously, `sp` was used, which held a stale `SP_EL0` snapshot from the last restricted mode exit. Because the profiler interrupts the thread mid-execution, Starnix's `sync_stack_ptr()` never runs to update `sp`, causing truncated captures.
2. Re-arms the collection task on transient failures.
3. Removes dead error-logging block for `ForEachProcess` since the lambda now returns `void` to ignore transient errors and ensure all threads are processed.
4. Refactors GetRestrictedSP.

TAG=agy
CONV=43088d97-9bb5-4f47-8d30-9e142db05d81

Original-Original-Bug: 524351849
Test: fx build
Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1666003
Original-Original-Revision: f3fe2b4315ce5ad045904e8511c2d0e453f99ccd
GitOrigin-RevId: 622a82c5fc5e731893a4d01c2919b17a85090452
Change-Id: Ia507029e8d8f884b24d8bef72fcf2038244fa08d
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1674876
Cr-Commit-Position: refs/heads/main@{#195392}
diff --git a/stem b/stem
index 58c4986..342cff7 100644
--- a/stem
+++ b/stem
@@ -8,6 +8,6 @@
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