fastbootd: Implement getvar all.

This implements getvar all by invoking each callback and writing an INFO
status for each result. For commands that take arguments, the variable
handler can specify a function that returns all possible arguments.
Currently this only applies to partition variables.

Bug: 78793464
Test: fastboot getvar all works
Change-Id: I1cf84e06bf67614b6f56171c0ee6ca5d7ac383c9
diff --git a/fastboot/device/variables.cpp b/fastboot/device/variables.cpp
index 8eeda98..9f3fa75 100644
--- a/fastboot/device/variables.cpp
+++ b/fastboot/device/variables.cpp
@@ -222,3 +222,37 @@
     *message = "yes";
     return true;
 }
+
+std::vector<std::vector<std::string>> GetAllPartitionArgsWithSlot(FastbootDevice* device) {
+    std::vector<std::vector<std::string>> args;
+    auto partitions = ListPartitions(device);
+    for (const auto& partition : partitions) {
+        args.emplace_back(std::initializer_list<std::string>{partition});
+    }
+    return args;
+}
+
+std::vector<std::vector<std::string>> GetAllPartitionArgsNoSlot(FastbootDevice* device) {
+    auto partitions = ListPartitions(device);
+
+    std::string slot_suffix = device->GetCurrentSlot();
+    if (!slot_suffix.empty()) {
+        auto names = std::move(partitions);
+        for (const auto& name : names) {
+            std::string slotless_name = name;
+            if (android::base::EndsWith(name, "_a") || android::base::EndsWith(name, "_b")) {
+                slotless_name = name.substr(0, name.rfind("_"));
+            }
+            if (std::find(partitions.begin(), partitions.end(), slotless_name) ==
+                partitions.end()) {
+                partitions.emplace_back(slotless_name);
+            }
+        }
+    }
+
+    std::vector<std::vector<std::string>> args;
+    for (const auto& partition : partitions) {
+        args.emplace_back(std::initializer_list<std::string>{partition});
+    }
+    return args;
+}