[#1273] 10_000-ZAT Miners fee

- Removed all uses of the incorrect 1000-ZAT fee as defined with  deprecated zip-313
- Default is now 10k zatoshi, the minimum defined by zip-317
- Changelog updated
- Closes  #1273

CHANGELOG.md

@@ -10,6 +10,9 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `PersistableWallet` API provides a new `endpoint` parameter of type `LightWalletEndpoint`, which could be used for 
   the Lightwalletd server customization. The new parameter is part of PersistableWallet persistence. The SDK handles 
   the persistence migration internally.
+- The **1_000** Zatoshi fee proposed in ZIP-313 is deprecated now, so the minimum is **10_000** Zatoshi, defined in 
+  ZIP-317—the ZcashSdk.MINERS_FEE now returns the correct value as described above. Note that the actual fee is 
+  handled in a rust layer.
 
 ## [2.0.0] - 2023-09-25
 

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/balance/view/BalanceView.kt

@@ -154,6 +154,8 @@ private fun BalanceMainContent(
             )
         )
 
+        // TODO [#776]: Support variable fees
+        // TODO [#776]: https://github.com/zcash/zcash-android-wallet-sdk/issues/776
         // This check will not be correct with variable fees
         if (walletSnapshot.transparentBalance.available > ZcashSdk.MINERS_FEE) {
             // Note this implementation does not guard against multiple clicks

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletSnapshot.kt

@@ -16,9 +16,11 @@ data class WalletSnapshot(
     val progress: PercentDecimal,
     val synchronizerError: SynchronizerError?
 ) {
+    // TODO [#776]: Support variable fees
+    // TODO [#776]: https://github.com/zcash/zcash-android-wallet-sdk/issues/776
     // Note: the wallet is effectively empty if it cannot cover the miner's fee
     val hasFunds = saplingBalance.available.value >
-        (ZcashSdk.MINERS_FEE.value.toDouble() / Zatoshi.ZATOSHI_PER_ZEC) // 0.00001
+        (ZcashSdk.MINERS_FEE.value.toDouble() / Zatoshi.ZATOSHI_PER_ZEC) // 0.0001
     val hasSaplingBalance = saplingBalance.total.value > 0
 
     val isSendEnabled: Boolean get() = status == Synchronizer.Status.SYNCED && hasFunds

sdk-lib/src/main/java/cash/z/ecc/android/sdk/ext/ZcashSdk.kt

@@ -14,7 +14,7 @@ object ZcashSdk {
     /**
      * Miner's fee in zatoshi.
      */
-    val MINERS_FEE = Zatoshi(1_000L)
+    val MINERS_FEE = Zatoshi(10_000L)
 
     /**
      * The maximum length of a memo.