Update stack trace test goldens to handle engine builds with lazy async stacks (#51216)

The next engine roll will introduce --lazy-async-stacks, which affects the
contents of stack traces.  This updates test expectations to match both the
old and new stack trace formats.

dev/automated_tests/flutter_test/exception_handling_expectation.txt

diff --git a/dev/automated_tests/flutter_test/exception_handling_expectation.txt b/dev/automated_tests/flutter_test/exception_handling_expectation.txt
index ef37011..2a5f54e 100644
--- a/dev/automated_tests/flutter_test/exception_handling_expectation.txt
+++ b/dev/automated_tests/flutter_test/exception_handling_expectation.txt
@@ -9,7 +9,7 @@
 #(1|2)      .+ \(package:flutter_test[/\\]src[/\\]widget_tester\.dart:[0-9]+:[0-9]+\)
 <asynchronous suspension>
 <<skip until matching line>>
-^\(elided [0-9]+ frames.+$
+^\(elided ([0-9]+|one) frame.+$
 <<skip until matching line>>
 The test description was:
 Exception handling in test harness - string
@@ -29,7 +29,7 @@
 #(1|2)      .+ \(package:flutter_test[/\\]src[/\\]widget_tester\.dart:[0-9]+:[0-9]+\)
 <asynchronous suspension>
 <<skip until matching line>>
-^\(elided [0-9]+ .+$
+^\(elided ([0-9]+|one) .+$
 <<skip until matching line>>
 The test description was:
 Exception handling in test harness - FlutterError
@@ -52,7 +52,7 @@
 <<skip until matching line>>
 #[0-9]+ +.+ \(package:flutter_test[/\\]src[/\\]widget_tester\.dart:[0-9]+:[0-9]+\)
 <<skip until matching line>>
-^\(elided [0-9]+ .+$
+^\(elided ([0-9]+|one) .+$
 <<skip until matching line>>
 The test description was:
 Exception handling in test harness - uncaught Future error

dev/automated_tests/flutter_test/test_async_utils_unguarded_expectation.txt

diff --git a/dev/automated_tests/flutter_test/test_async_utils_unguarded_expectation.txt b/dev/automated_tests/flutter_test/test_async_utils_unguarded_expectation.txt
index c5b94b9..04e7904 100644
--- a/dev/automated_tests/flutter_test/test_async_utils_unguarded_expectation.txt
+++ b/dev/automated_tests/flutter_test/test_async_utils_unguarded_expectation.txt
@@ -15,11 +15,11 @@
 
 When the first method was called, this was the stack:
 <<skip until matching line>>
-(elided [0-9]+ frames from .+)
+(elided ([0-9]+|one) frames? from .+)
 
 When the exception was thrown, this was the stack:
 <<skip until matching line>>
-(elided [0-9]+ frames from .+)
+(elided ([0-9]+|one) frames? from .+)
 
 The test description was:
 TestAsyncUtils - handling unguarded async helper functions