Disable try_reserve tests on Android

src/liballoc/tests/string.rs

@@ -555,6 +555,7 @@ fn test_reserve_exact() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve() {
     // These are the interesting cases:
     // * exactly isize::MAX should never trigger a CapacityOverflow (can be OOM)
@@ -644,6 +645,7 @@ fn test_try_reserve() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve_exact() {
     // This is exactly the same as test_try_reserve with the method changed.
     // See that test for comments.

src/liballoc/tests/vec.rs

@@ -1137,6 +1137,7 @@ fn test_reserve_exact() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve() {
     // These are the interesting cases:
     // * exactly isize::MAX should never trigger a CapacityOverflow (can be OOM)
@@ -1254,6 +1255,7 @@ fn test_try_reserve() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve_exact() {
     // This is exactly the same as test_try_reserve with the method changed.
     // See that test for comments.

src/liballoc/tests/vec_deque.rs

@@ -1134,6 +1134,7 @@ fn test_reserve_exact_2() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve() {
     // These are the interesting cases:
     // * exactly isize::MAX should never trigger a CapacityOverflow (can be OOM)
@@ -1248,6 +1249,7 @@ fn test_try_reserve() {
 
 #[test]
 #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve_exact() {
     // This is exactly the same as test_try_reserve with the method changed.
     // See that test for comments.